Vector Graphics rendering of GPAC. More...

Data Structures
struct	GF_EVGFragmentParam

struct	GF_EVGVertexParam

Typedefs
typedef void(*	gf_evg_texture_callback) (void cbk, u32 x, u32 y, Float r, Float g, Float b, Float *a)

typedef u8(*	gf_evg_get_alpha) (void *udta, u8 src_alpha, s32 x, s32 y)

typedef Bool(*	gf_evg_fragment_shader) (void udta, GF_EVGFragmentParam fragp)

typedef Bool(*	gf_evg_fragment_shader_init) (void udta, GF_EVGFragmentParam fragp, u32 th_id, Bool is_cleanup)

typedef Bool(*	gf_evg_vertex_shader) (void udta, GF_EVGVertexParam vertp)

Enumerations
enum	GF_StencilType { GF_STENCIL_SOLID = 0 , GF_STENCIL_LINEAR_GRADIENT , GF_STENCIL_RADIAL_GRADIENT , GF_STENCIL_VERTEX_GRADIENT , GF_STENCIL_TEXTURE }

enum	GF_GradientMode { GF_GRADIENT_MODE_PAD , GF_GRADIENT_MODE_SPREAD , GF_GRADIENT_MODE_REPEAT }

enum	GF_TextureMapFlags { GF_TEXTURE_REPEAT_S = (1<<1) , GF_TEXTURE_REPEAT_T = (1<<2) , GF_TEXTURE_FLIP_X = (1<<3) , GF_TEXTURE_FLIP_Y = (1<<4) }

enum	GF_TextureFilter { GF_TEXTURE_FILTER_HIGH_SPEED , GF_TEXTURE_FILTER_MID , GF_TEXTURE_FILTER_HIGH_QUALITY }

enum	GF_RasterQuality { GF_RASTER_HIGH_SPEED , GF_RASTER_MID , GF_RASTER_HIGH_QUALITY }

enum	GF_EVGMultiTextureMode { GF_EVG_OPERAND_NONE = 0 , GF_EVG_OPERAND_MIX , GF_EVG_OPERAND_MIX_ALPHA , GF_EVG_OPERAND_REPLACE_ALPHA , GF_EVG_OPERAND_REPLACE_ONE_MINUS_ALPHA , GF_EVG_OPERAND_MIX_DYN , GF_EVG_OPERAND_MIX_DYN_ALPHA , GF_EVG_OPERAND_ODD_FILL }

enum	GF_EVGCompositeMode { GF_EVG_SRC_OVER = 0 , GF_EVG_SRC_ATOP , GF_EVG_SRC_IN , GF_EVG_SRC_OUT , GF_EVG_DST_ATOP , GF_EVG_DST_IN , GF_EVG_DST_OUT , GF_EVG_DST_OVER , GF_EVG_LIGHTER , GF_EVG_COPY , GF_EVG_XOR }

enum	GF_EVGPrimitiveType { GF_EVG_POINTS =1 , GF_EVG_POLYGON , GF_EVG_LINES , GF_EVG_TRIANGLES , GF_EVG_QUADS , GF_EVG_LINE_STRIP , GF_EVG_TRIANGLE_STRIP , GF_EVG_TRIANGLE_FAN , GF_EVG_QUAD_STRIP }

enum	GF_EVGDepthTest { GF_EVGDEPTH_DISABLE , GF_EVGDEPTH_NEVER , GF_EVGDEPTH_ALWAYS , GF_EVGDEPTH_EQUAL , GF_EVGDEPTH_NEQUAL , GF_EVGDEPTH_LESS , GF_EVGDEPTH_LESS_EQUAL , GF_EVGDEPTH_GREATER , GF_EVGDEPTH_GREATER_EQUAL }

enum	GF_EVGFragmentType { GF_EVG_FRAG_INVALID = 0 , GF_EVG_FRAG_RGB , GF_EVG_FRAG_RGB_PACK , GF_EVG_FRAG_YUV , GF_EVG_FRAG_YUV_PACK }

enum	GF_EVGMaskMode { GF_EVGMASK_NONE = 0 , GF_EVGMASK_DRAW , GF_EVGMASK_DRAW_NO_CLEAR , GF_EVGMASK_USE , GF_EVGMASK_USE_INV , GF_EVGMASK_RECORD }

Functions
GF_EVGStencil *	gf_evg_stencil_new (GF_StencilType type)

void	gf_evg_stencil_delete (GF_EVGStencil *stencil)

GF_Err	gf_evg_stencil_set_matrix (GF_EVGStencil stencil, GF_Matrix2D mat)

Bool	gf_evg_stencil_get_matrix (GF_EVGStencil stencil, GF_Matrix2D mat)

GF_Err	gf_evg_stencil_set_auto_matrix (GF_EVGStencil *stencil, Bool auto_on)

Bool	gf_evg_stencil_get_auto_matrix (GF_EVGStencil *stencil)

GF_StencilType	gf_evg_stencil_type (GF_EVGStencil *stencil)

GF_Err	gf_evg_stencil_set_brush_color (GF_EVGStencil *stencil, GF_Color color)

GF_Color	gf_evg_stencil_get_brush_color (GF_EVGStencil *stencil)

GF_Err	gf_evg_stencil_set_gradient_mode (GF_EVGStencil *stencil, GF_GradientMode mode)

GF_Err	gf_evg_stencil_set_linear_gradient (GF_EVGStencil *stencil, Fixed start_x, Fixed start_y, Fixed end_x, Fixed end_y)

GF_Err	gf_evg_stencil_set_radial_gradient (GF_EVGStencil *stencil, Fixed cx, Fixed cy, Fixed fx, Fixed fy, Fixed x_radius, Fixed y_radius)

GF_Err	gf_evg_stencil_set_gradient_interpolation (GF_EVGStencil stencil, Fixed pos, GF_Color *col, u32 count)

GF_Err	gf_evg_stencil_push_gradient_interpolation (GF_EVGStencil *stencil, Fixed pos, GF_Color col)

GF_Err	gf_evg_stencil_set_alpha (GF_EVGStencil *stencil, u8 alpha)

u8	gf_evg_stencil_get_alpha (GF_EVGStencil *stencil)

Bool	gf_evg_texture_format_ok (GF_PixelFormat pixelFormat)

GF_Err	gf_evg_stencil_set_texture (GF_EVGStencil stencil, u8 pixels, u32 width, u32 height, u32 stride, GF_PixelFormat pixelFormat)

GF_Err	gf_evg_stencil_set_texture_planes (GF_EVGStencil stencil, u32 width, u32 height, GF_PixelFormat pixelFormat, const u8 y_or_rgb, u32 stride, const u8 u_plane, const u8 v_plane, u32 uv_stride, const u8 *alpha_plane, u32 alpha_stride)

GF_Err	gf_evg_stencil_set_palette (GF_EVGStencil stencil, const u8 palette, u32 pix_fmt, u32 nb_cols)

GF_Err	gf_evg_stencil_set_texture_parametric (GF_EVGStencil stencil, u32 width, u32 height, GF_PixelFormat pixelFormat, gf_evg_texture_callback callback, void cbk_udta, Bool use_screen_coords)

GF_Err	gf_evg_stencil_set_mapping (GF_EVGStencil *stencil, GF_TextureMapFlags map_mode)

GF_Err	gf_evg_stencil_set_pad_color (GF_EVGStencil *stencil, GF_Color pad_color)

u32	gf_evg_stencil_get_pad_color (GF_EVGStencil *stencil)

GF_Err	gf_evg_stencil_set_filter (GF_EVGStencil *stencil, GF_TextureFilter filter_mode)

GF_Err	gf_evg_stencil_set_color_matrix (GF_EVGStencil stencil, GF_ColorMatrix cmat)

GF_Err	gf_evg_stencil_get_color_matrix (GF_EVGStencil stencil, GF_ColorMatrix cmat)

u32	gf_evg_stencil_get_pixel (GF_EVGStencil *stencil, s32 x, s32 y)

u32	gf_evg_stencil_get_pixel_yuv (GF_EVGStencil *stencil, s32 x, s32 y)

u64	gf_evg_stencil_get_pixel_wide (GF_EVGStencil *stencil, s32 x, s32 y)

u64	gf_evg_stencil_get_pixel_yuv_wide (GF_EVGStencil *stencil, s32 x, s32 y)

GF_Vec4	gf_evg_stencil_get_pixel_f (GF_EVGStencil *stencil, Float x, Float y)

GF_Vec4	gf_evg_stencil_get_pixel_yuv_f (GF_EVGStencil *stencil, Float x, Float y)

GF_EVGSurface *	gf_evg_surface_new (Bool center_coords)

void	gf_evg_surface_delete (GF_EVGSurface *surf)

GF_Err	gf_evg_enable_threading (GF_EVGSurface *surf, s32 nb_threads)

GF_Err	gf_evg_surface_attach_to_texture (GF_EVGSurface surf, GF_EVGStencil sten)

Bool	gf_evg_surface_format_ok (GF_PixelFormat pixelFormat)

GF_Err	gf_evg_surface_attach_to_buffer (GF_EVGSurface surf, u8 pixels, u32 width, u32 height, s32 pitch_x, s32 pitch_y, GF_PixelFormat pixelFormat)

GF_Err	gf_evg_surface_set_raster_level (GF_EVGSurface *surf, GF_RasterQuality level)

GF_RasterQuality	gf_evg_surface_get_raster_level (GF_EVGSurface *surf)

GF_Err	gf_evg_surface_force_aa (GF_EVGSurface *surf)

GF_Err	gf_evg_surface_set_matrix (GF_EVGSurface surf, GF_Matrix2D mat)

GF_Err	gf_evg_surface_set_matrix_3d (GF_EVGSurface surf, GF_Matrix mat)

GF_Err	gf_evg_surface_set_clipper (GF_EVGSurface surf, GF_IRect rc)

Bool	gf_evg_surface_use_clipper (GF_EVGSurface *surf)

GF_Err	gf_evg_surface_set_path (GF_EVGSurface surf, GF_Path path)

GF_Err	gf_evg_surface_fill (GF_EVGSurface surf, GF_EVGStencil stencil)

GF_Err	gf_evg_surface_multi_fill (GF_EVGSurface surf, GF_EVGMultiTextureMode operand, GF_EVGStencil sten1, GF_EVGStencil sten2, GF_EVGStencil sten3, Float params[4])

GF_Err	gf_evg_surface_clear (GF_EVGSurface surf, GF_IRect rc, GF_Color col)

void	gf_evg_surface_set_center_coords (GF_EVGSurface *surf, Bool center_coords)

void	gf_evg_surface_set_composite_mode (GF_EVGSurface *surf, GF_EVGCompositeMode comp_mode)

void	gf_evg_surface_set_alpha_callback (GF_EVGSurface surf, gf_evg_get_alpha get_alpha, void cbk)

GF_Err	gf_evg_surface_enable_3d (GF_EVGSurface *surf)

GF_Err	gf_evg_surface_set_projection (GF_EVGSurface surf, GF_Matrix mx)

GF_Err	gf_evg_surface_set_modelview (GF_EVGSurface surf, GF_Matrix mx)

GF_Err	gf_evg_surface_draw_array (GF_EVGSurface surf, u32 indices, u32 nb_indices, Float *vertices, u32 nb_vertices, u32 nb_comp, GF_EVGPrimitiveType prim_type)

GF_Err	gf_evg_surface_clear_depth (GF_EVGSurface *surf, Float depth)

GF_Err	gf_evg_surface_viewport (GF_EVGSurface *surf, u32 x, u32 y, u32 w, u32 h)

GF_Err	gf_evg_surface_draw_path (GF_EVGSurface surf, GF_Path path, Float z)

GF_Err	gf_evg_set_depth_test (GF_EVGSurface *surf, GF_EVGDepthTest mode)

GF_Err	gf_evg_surface_set_fragment_shader (GF_EVGSurface surf, gf_evg_fragment_shader shader, gf_evg_fragment_shader_init shader_init, void shader_udta)

GF_Err	gf_evg_surface_set_vertex_shader (GF_EVGSurface surf, gf_evg_vertex_shader shader, void shader_udta)

GF_Err	gf_evg_surface_set_ccw (GF_EVGSurface *surf, Bool is_ccw)

GF_Err	gf_evg_surface_set_backcull (GF_EVGSurface *surf, Bool backcull)

GF_Err	gf_evg_surface_set_antialias (GF_EVGSurface *surf, Bool antialias)

GF_Err	gf_evg_surface_set_min_depth (GF_EVGSurface *surf, Float min_depth)

GF_Err	gf_evg_surface_set_max_depth (GF_EVGSurface *surf, Float max_depth)

GF_Err	gf_evg_surface_set_clip_zero (GF_EVGSurface *surf, Bool clip_zero)

GF_Err	gf_evg_surface_set_point_size (GF_EVGSurface *surf, Float size)

GF_Err	gf_evg_surface_set_line_size (GF_EVGSurface *surf, Float size)

GF_Err	gf_evg_surface_set_point_smooth (GF_EVGSurface *surf, Bool smooth)

GF_Err	gf_evg_surface_disable_early_depth (GF_EVGSurface *surf, Bool disable)

GF_Err	gf_evg_surface_write_depth (GF_EVGSurface *surf, Bool do_write)

GF_Err	gf_evg_surface_set_depth_buffer (GF_EVGSurface surf, Float depth)

GF_Err	gf_gf_evg_rgb_to_yuv_f (GF_EVGSurface surf, Float r, Float g, Float b, Float y, Float cb, Float cr)

GF_Err	gf_evg_yuv_to_rgb_f (GF_EVGSurface surf, Float y, Float cb, Float cr, Float r, Float g, Float b)

void	gf_evg_rgb_to_yuv (GF_EVGSurface surf, GF_Color col, u8 y, u8 cb, u8 cr)

GF_Color	gf_evg_argb_to_ayuv (GF_EVGSurface *surf, GF_Color col)

GF_Color	gf_evg_ayuv_to_argb (GF_EVGSurface *surf, GF_Color col)

u64	gf_evg_argb_to_ayuv_wide (GF_EVGSurface *surf, u64 col)

u64	gf_evg_ayuv_to_argb_wide (GF_EVGSurface *surf, u64 col)

GF_Err	gf_evg_surface_set_mask_mode (GF_EVGSurface *surf, GF_EVGMaskMode mask_mode)

GF_EVGMaskMode	gf_evg_surface_get_mask_mode (GF_EVGSurface *surf)

Detailed Description

GPAC uses a software rasterizer for vector graphics based on FreeType's "ftgray" anti-aliased renderer.

The rasterizer supports

drawing to RGB, YUV and grayscale surfaces.
Texture mapping using RGB, YUV and grayscale textures
Linear Gradients with opacity
Radial Gradients with opacity
Solid brush with opacity
axis-aligned clipping

The rasterizer is only capable of filling a given GF_Path object

striking (outlining) of a path must be done by using gf_path_get_outline to the the outline path
text must be first converted to GF_Path

The rasterizer also supports experimental drawing of 3D primitives (point, lines, triangles). This is obviously not intended to replace GPU rendering, but can be useful to draw simple primitives over an existing video source. The following constraints apply in 3D mode:

stencils are not used
path can only be drawn using gf_evg_surface_draw_path

Data Structure Documentation

◆ GF_EVGFragmentParam

struct GF_EVGFragmentParam

Parameters for the fragment callback

Collaboration diagram for GF_EVGFragmentParam:

Data Fields
Float	screen_x	screen x in pixels - input param
Float	screen_y	screen y in pixels - input param
Float	screen_z	screen z in NDC - input param
Float	depth	depth - input and output param - 3D shaders only
u32	prim_index	primitive index in the current gf_evg_surface_draw_array call, 0 being the first primitive - input param - 3D shaders only
u32	idx1	index of first vertex in the current primitive - input param - 3D shaders only
u32	idx2	index of second vertex in the current primitive (for lines or triangles/quads) - input param - 3D shaders only
u32	idx3	index of third vertex in the current primitive (for triangles/quads) - input param - 3D shaders only
GF_EVGPrimitiveType	ptype	primitive type - input param - 3D shaders only
GF_Vec4	color	fragment color, must be written if fragment is not discarded - output value
u32	color_pack	fragment color in pack 32 bit ARGB/AYUV
u64	color_pack_wide	fragment color in pack 64 bit ARGB/AYUV
GF_EVGFragmentType	frag_valid	fragment valid state - output value
Float	pbc1	perspective corrected barycentric, eg bc1/q1, bc2/q2, bc3/q3 - 3D shaders only
Float	pbc2
Float	pbc3
Float	persp_denum	perspective divider - 3D shaders only Note this is also 1/W of the fragment, eg opengl gl_fragCoord.w
void *	shader_udta
u32	tx_x	horizontal texture coordinate, 0 is left of image - 2D shaders only
u32	tx_y	vertical texture coordinate, 0 is top of image - 2D shaders only
u32	tx_width	texture width - 2D shaders only
u32	tx_height	texture height - 2D shaders only
u8	coverage	coverage value between 0 and 0xFF - 2D shaders only
u8	odd_flag	odd / even flag for path drawn with zero/non-zero fill rule - 2D shaders only

◆ GF_EVGVertexParam

struct GF_EVGVertexParam

Parameters for the vertex callback

Collaboration diagram for GF_EVGVertexParam:

Data Fields
GF_Vec4	in_vertex	input vertex - input param
u32	prim_index	primitive index in the current gf_evg_surface_draw_array call, 0 being the first primitive - input param
u32	vertex_idx	index of the vertex - input param
u32	vertex_idx_in_prim	index of the vertex in the current primitive - input param
u32	ptype	primitive type - input param
GF_Vec4	out_vertex	transformed vertex to use, must be written - output values

Typedef Documentation

◆ gf_evg_texture_callback

typedef void(* gf_evg_texture_callback) (void *cbk, u32 x, u32 y, Float *r, Float *g, Float *b, Float *a)

callback function prototype for parametric textures

Parameters

cbk	user data callback
x	horizontal coordinate in texture, ranging between 0 and width-1, (0,0) being top-left pixel, or horizontal coordinate of destination pixel on surface
y	vertical coordinate in texture, ranging between 0 and height-1, (0,0) being top-left pixel, or vertical coordinate of destination pixel on surface
r	set to the red value (not initialized before call)
g	set to the green value (not initialized before call)
b	set to the blue value (not initialized before call)
a	set to the alpha value (not initialized before call)

◆ gf_evg_get_alpha

typedef u8(* gf_evg_get_alpha) (void *udta, u8 src_alpha, s32 x, s32 y)

callback type for alpha override

Parameters

udta	opaque data passed back to caller
src_alpha	alpha value about to be blended
x	horizontal coordinate of pixel to be drawn, {0,0} being top-left, positive Y go down
y	vertical coordinate of pixel to be drawn, {0,0} being top-left, positive Y go down

Returns: final alpha value to use

◆ gf_evg_fragment_shader

typedef Bool(* gf_evg_fragment_shader) (void *udta, GF_EVGFragmentParam *fragp)

callback type for fragment shader

Parameters

udta	opaque data passed back to caller
fragp	fragment paramters

Returns: GF_TRUE if success; GF_FALSE if error

◆ gf_evg_fragment_shader_init

typedef Bool(* gf_evg_fragment_shader_init) (void *udta, GF_EVGFragmentParam *fragp, u32 th_id, Bool is_cleanup)

callback type for fragment shader init, called once before each primitive - may be NULL

Parameters

udta	opaque data passed back to caller
fragp	fragment paramters
th_id	index of thread context
is_cleanup	if TRUE indicates and of primitive rendering, otherwise begin

Returns: GF_TRUE if success; GF_FALSE if error

◆ gf_evg_vertex_shader

typedef Bool(* gf_evg_vertex_shader) (void *udta, GF_EVGVertexParam *vertp)

callback type for vertex shader

Parameters

udta	opaque data passed back to caller
vertp	vertex paramters

Returns: GF_TRUE if success; GF_FALSE if error

Enumeration Type Documentation

◆ GF_StencilType

enum GF_StencilType

stencil types

Enumerator
GF_STENCIL_SOLID	solid color stencil
GF_STENCIL_LINEAR_GRADIENT	linear color gradient stencil
GF_STENCIL_RADIAL_GRADIENT	radial color gradient stencil
GF_STENCIL_VERTEX_GRADIENT	texture stencil
GF_STENCIL_TEXTURE	texture stencil

◆ GF_GradientMode

enum GF_GradientMode

gradient filling modes

Enumerator
GF_GRADIENT_MODE_PAD	edge colors are repeated until path is filled
GF_GRADIENT_MODE_SPREAD	pattern is inversed each time it's repeated
GF_GRADIENT_MODE_REPEAT	pattern is repeated to fill path

◆ GF_TextureMapFlags

enum GF_TextureMapFlags

texture map flags

Enumerator
GF_TEXTURE_REPEAT_S	texture is repeated in its horizontal direction
GF_TEXTURE_REPEAT_T	texture is repeated in its horizontal direction
GF_TEXTURE_FLIP_X	texture is fliped horizontally
GF_TEXTURE_FLIP_Y	texture is fliped vertically

◆ GF_TextureFilter

enum GF_TextureFilter

filter levels for texturing - up to the graphics engine but the following levels are used by the client

Enumerator
GF_TEXTURE_FILTER_HIGH_SPEED	high speed mapping (ex, no filtering applied)
GF_TEXTURE_FILTER_MID	compromise between speed and quality (ex, filter to nearest pixel)
GF_TEXTURE_FILTER_HIGH_QUALITY	high quality mapping (ex, bi-linear/bi-cubic interpolation)

◆ GF_RasterQuality

enum GF_RasterQuality

rasterizer antialiasing depending on the graphics engine

Enumerator
GF_RASTER_HIGH_SPEED	raster shall use no antialiasing
GF_RASTER_MID	raster should use fast mode and good quality if possible
GF_RASTER_HIGH_QUALITY	raster should use full antialiasing - this is the default for all new surfaces

◆ GF_EVGMultiTextureMode

enum GF_EVGMultiTextureMode

Operands for multitexture operations

Enumerator
GF_EVG_OPERAND_NONE	no multitexture
GF_EVG_OPERAND_MIX	mix texture 1 and texure 2 using coefficient in first param, returning tx1coef + tx2(1-coef) but forcing alpha to full opacity
GF_EVG_OPERAND_MIX_ALPHA	mix texture 1 and texure 2 using coefficient in first param, returning tx1coef + tx2(1-coef), including alpha channel
GF_EVG_OPERAND_REPLACE_ALPHA	replace alpha of texture 1 with alpha of texture 2 if first param is 0 or not set, use alpha channel from texture 2 if first param is 1, use red channel from texture 2 if first param is 2, use green/Cb/U channel from texture 2 if first param is 3, use blue/Cr/V channel from texture 2
GF_EVG_OPERAND_REPLACE_ONE_MINUS_ALPHA	replace alpha of texture 1 with (1-alpha) of texture 2 if first param is 0 or not set, use alpha channel from texture 2 if first param is 1, use red/Y channel from texture 2 if first param is 2, use green/Cb/U channel from texture 2 if first param is 3, use blue/Cr/V channel from texture 2
GF_EVG_OPERAND_MIX_DYN	mix texture 1 and texure 2 using alpha coef of texture 3 but forcing alpha to full opacity if first param is 0 or not set, use alpha channel from texture 3 if first param is 1, use red channel from texture 3 if first param is 2, use green/Cb/U channel from texture 3 if first param is 3, use blue/Cr/V channel from texture 3
GF_EVG_OPERAND_MIX_DYN_ALPHA	mix texture 1 and texure 2 using alpha coef of texture 3, including alpha channel. if first param is 0 or not set, use alpha channel from texture 3 if first param is 1, use red channel from texture 3 if first param is 2, use green/Cb/U channel from texture 3 if first param is 3, use blue/Cr/V channel from texture 3
GF_EVG_OPERAND_ODD_FILL	use texture 1 for odd fill and texture 2 for even fill

◆ GF_EVGCompositeMode

enum GF_EVGCompositeMode

Composition mode used for ARGB surfaces - cf Canvas2D modes

Enumerator
GF_EVG_SRC_OVER	source over
GF_EVG_SRC_ATOP	source atop
GF_EVG_SRC_IN	source in
GF_EVG_SRC_OUT	source out
GF_EVG_DST_ATOP	destination atop
GF_EVG_DST_IN	destination in
GF_EVG_DST_OUT	destination out
GF_EVG_DST_OVER	destination over
GF_EVG_LIGHTER	destination * source
GF_EVG_COPY	source copy
GF_EVG_XOR	source XOR destination

◆ GF_EVGPrimitiveType

enum GF_EVGPrimitiveType

Primitive types for 3D software rasterize - see OpenGL terminology

Enumerator
GF_EVG_POINTS	points, 1 vertex index per primitive
GF_EVG_POLYGON	polygon, all vertex indices in array are used for a single face
GF_EVG_LINES	lines, 2 vertex indices per primitive
GF_EVG_TRIANGLES	triangles, 3 vertex indices per primitive
GF_EVG_QUADS	quads, 4 vertex indices per primitive
GF_EVG_LINE_STRIP	line strip, 2 vertex indices for first primitive, then one for subsequent ones
GF_EVG_TRIANGLE_STRIP	triangle strip, 3 vertex indices for first primitive, then one for subsequent ones
GF_EVG_TRIANGLE_FAN	triangle fan, 3 vertex indices for first primitive, then one for subsequent ones
GF_EVG_QUAD_STRIP	quad strip, 4 vertex indices for first primitive, then one for subsequent ones

◆ GF_EVGDepthTest

enum GF_EVGDepthTest

Depth test modes

Enumerator
GF_EVGDEPTH_DISABLE	depth test is disabled
GF_EVGDEPTH_NEVER	depth test always fails
GF_EVGDEPTH_ALWAYS	depth test always succeeds
GF_EVGDEPTH_EQUAL	depth test succeeds if fragment depth is == than depth buffer value
GF_EVGDEPTH_NEQUAL	depth test succeeds if fragment depth is != than depth buffer value
GF_EVGDEPTH_LESS	depth test succeeds if fragment depth is < than depth buffer value
GF_EVGDEPTH_LESS_EQUAL	depth test succeeds if fragment depth is <= than depth buffer value
GF_EVGDEPTH_GREATER	depth test succeeds if fragment depth is > than depth buffer value
GF_EVGDEPTH_GREATER_EQUAL	depth test succeeds if fragment depth is >= than depth buffer value

◆ GF_EVGFragmentType

enum GF_EVGFragmentType

fragment color type

Enumerator
GF_EVG_FRAG_INVALID	fragment is invalid (discarded or error)
GF_EVG_FRAG_RGB	fragment is RGB float
GF_EVG_FRAG_RGB_PACK
GF_EVG_FRAG_YUV	fragment is YUV
GF_EVG_FRAG_YUV_PACK

◆ GF_EVGMaskMode

enum GF_EVGMaskMode

global alpha mask values

Enumerator
GF_EVGMASK_NONE	global alpha mask not used
GF_EVGMASK_DRAW	subsequent draw operations will target the global alpha mask
GF_EVGMASK_DRAW_NO_CLEAR	subsequent draw operations will target the global alpha mask, but alpha mask is not cleared
GF_EVGMASK_USE	subsequent draw operations will be filtered with the global alpha mask
GF_EVGMASK_USE_INV	subsequent draw operations will be filtered with 1 minus the global alpha mask
GF_EVGMASK_RECORD	combine draw and use: the mask is set to 0xFF, each pixel drawn turns the mask value to 0

Function Documentation

◆ gf_evg_stencil_new()

GF_EVGStencil* gf_evg_stencil_new ( GF_StencilType type )

common constructor for all stencil types

Parameters

type	the stencil type

Returns: a new stencil object

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◆ gf_evg_stencil_delete()

void gf_evg_stencil_delete ( GF_EVGStencil * stencil )

common destructor for all stencils

Parameters

stencil the target stencil

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◆ gf_evg_stencil_set_matrix()

GF_Err gf_evg_stencil_set_matrix	(	GF_EVGStencil *	stencil,
		GF_Matrix2D *	mat
	)

sets stencil transformation matrix

Parameters

stencil	the target stencil
mat	the 2D matrix to set

Returns: error if any

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◆ gf_evg_stencil_get_matrix()

Bool gf_evg_stencil_get_matrix	(	GF_EVGStencil *	stencil,
		GF_Matrix2D *	mat
	)

gets stencil transformation matrix

Parameters

stencil	the target stencil
mat	the 2D matrix to fetch

Returns: TRUE if resulting matrix is fetched, false otherwise (matrix is identity or does not apply to this stencil class)

◆ gf_evg_stencil_set_auto_matrix()

GF_Err gf_evg_stencil_set_auto_matrix	(	GF_EVGStencil *	stencil,
		Bool	auto_on
	)

sets stencil transformation matrix auto mode.

When auto matrix mode is activated, the stencil matrix only describes texture mapping transform in uv space (normalized UV coordinates, OpenGL like), and final transformation to raster coordinates is done internally. When auto matrix mode is not activated,, the stencil matrix must describe the complete transformation from uv space to raster coordinates (consequently, the matrix usually includes the final path transformation).

Stencils are by default created in auto matrix mode.

Parameters

stencil	the target stencil
auto_on	If true, the surface current matrix will be added to the stencil matrix when drawing, otherwise the stencil matrix is in final surface coordinates

Returns: error if any

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◆ gf_evg_stencil_get_auto_matrix()

Bool gf_evg_stencil_get_auto_matrix ( GF_EVGStencil * stencil )

sets stencil transformation matrix auto mode.

Parameters

stencil the target stencil

Returns: true if auto mode is enabled, false otherwise

◆ gf_evg_stencil_type()

GF_StencilType gf_evg_stencil_type ( GF_EVGStencil * stencil )

gets stencil type

Parameters

stencil the target stencil

Returns: stencil type

◆ gf_evg_stencil_set_brush_color()

GF_Err gf_evg_stencil_set_brush_color	(	GF_EVGStencil *	stencil,
		GF_Color	color
	)

sets color for solid brush stencil

Parameters

stencil	the target stencil
color	the color to set

Returns: error if any

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◆ gf_evg_stencil_get_brush_color()

GF_Color gf_evg_stencil_get_brush_color ( GF_EVGStencil * stencil )

gets color for solid brush stencil

Parameters

stencil the target stencil

Returns: the stencil color

◆ gf_evg_stencil_set_gradient_mode()

GF_Err gf_evg_stencil_set_gradient_mode	(	GF_EVGStencil *	stencil,
		GF_GradientMode	mode
	)

sets gradient repeat mode for a gradient stencil

Note: this may be called before the gradient is setup

Parameters

stencil	the target stencil
mode	the gradient mode

Returns: error if any

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◆ gf_evg_stencil_set_linear_gradient()

GF_Err gf_evg_stencil_set_linear_gradient	(	GF_EVGStencil *	stencil,
		Fixed	start_x,
		Fixed	start_y,
		Fixed	end_x,
		Fixed	end_y
	)

sets linear gradient direction for a gradient stencil Gradient line is defined by start and end. For example, {0,0}, {1,0} defines an horizontal gradient

Parameters

stencil	the target stencil
start_x	horizontal coordinate of starting point
start_y	vertical coordinate of starting point
end_x	horizontal coordinate of ending point
end_y	vertical coordinate of ending point

Returns: error if any

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◆ gf_evg_stencil_set_radial_gradient()

GF_Err gf_evg_stencil_set_radial_gradient	(	GF_EVGStencil *	stencil,
		Fixed	cx,
		Fixed	cy,
		Fixed	fx,
		Fixed	fy,
		Fixed	x_radius,
		Fixed	y_radius
	)

sets radial gradient center point, focal point and radius for a gradient stencil

Parameters

stencil	the target stencil
cx	horizontal coordinate of center
cy	vertical coordinate of center
fx	horizontal coordinate of focal point
fy	vertical coordinate of focal point
x_radius	horizontal radius
y_radius	vertical radius

Returns: error if any

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◆ gf_evg_stencil_set_gradient_interpolation()

GF_Err gf_evg_stencil_set_gradient_interpolation	(	GF_EVGStencil *	stencil,
		Fixed *	pos,
		GF_Color *	col,
		u32	count
	)

sets color interpolation for a gradient stencil

Note: the colors at 0 and 1.0 MUST be provided; colors shall be fed in order from 0 to 1

Parameters

stencil	the target stencil
pos	interpolation positions. Each position gives the distance from (center for radial, start for linear) expressed between 0 and 1 (1 being the gradient bounds) - may be NULL when count is 0
col	colors at the given position - may be NULL when count is 0
count	number of colors and position. A value of 0 resets the gradient colors

Returns: error if any

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◆ gf_evg_stencil_push_gradient_interpolation()

GF_Err gf_evg_stencil_push_gradient_interpolation	(	GF_EVGStencil *	stencil,
		Fixed	pos,
		GF_Color	col
	)

pushes a single color interpolation for a gradient stencil

Note: the colors at 0 and 1.0 MUST be provided; colors shall be fed in order from 0 to 1

Parameters

stencil	the target stencil
pos	interpolation position. A position gives the distance from (center for radial, start for linear) expressed between 0 and 1 (1 being the gradient bounds)
col	color at the given position

Returns: error if any

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◆ gf_evg_stencil_set_alpha()

GF_Err gf_evg_stencil_set_alpha	(	GF_EVGStencil *	stencil,
		u8	alpha
	)

sets global alpha blending level for a stencil The alpha channel will be combined with the color matrix if any

Warning: do not use with solid brush stencil

Parameters

stencil	the target stencil
alpha	the alpha value between 0 (full transparency) and 255 (full opacityy)

Returns: error if any

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◆ gf_evg_stencil_get_alpha()

u8 gf_evg_stencil_get_alpha ( GF_EVGStencil * stencil )

gets global alpha blending level of a stencil

Parameters

stencil the target stencil

Returns: the alpha value between 0 (full transparency) and 255 (full opacityy)

◆ gf_evg_texture_format_ok()

Bool gf_evg_texture_format_ok ( GF_PixelFormat pixelFormat )

checks if pixel format is supported for a texture stencil

Parameters

pixelFormat the target pixel format

Returns: GF_TRUE if supported, GF_FALSE otherwise

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◆ gf_evg_stencil_set_texture()

GF_Err gf_evg_stencil_set_texture	(	GF_EVGStencil *	stencil,
		u8 *	pixels,
		u32	width,
		u32	height,
		u32	stride,
		GF_PixelFormat	pixelFormat
	)

sets pixel data for a texture stencil

Parameters

stencil	the target stencil
pixels	texture data starting from top row
width	texture width in pixels
height	texture height in pixels
stride	texture horizontal pitch (bytes to skip to get to next row)
pixelFormat	texture pixel format

Note: this stencil acts as a data wrapper, the pixel data is not locally copied

Returns: error if any

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◆ gf_evg_stencil_set_texture_planes()

GF_Err gf_evg_stencil_set_texture_planes	(	GF_EVGStencil *	stencil,
		u32	width,
		u32	height,
		GF_PixelFormat	pixelFormat,
		const u8 *	y_or_rgb,
		u32	stride,
		const u8 *	u_plane,
		const u8 *	v_plane,
		u32	uv_stride,
		const u8 *	alpha_plane,
		u32	alpha_stride
	)

sets pixel planes data for a texture stencil

Parameters

stencil	the target stencil
width	texture width in pixels
height	texture height in pixels
pixelFormat	texture pixel format
y_or_rgb	Y plane or RGB plane
stride	stride of the Y or RGB plane
u_plane	U plane or UV plane for semi-planar YUV formats
v_plane	V plane for planar YUV format, NULL for semi-planar YUV formats
uv_stride	stride of the U and V or UV plane
alpha_plane	alpha plane
alpha_stride	stride of the alpha plane; if 0 and alpha plane is not NULL, the stride is assumed to be the same as the Y plane stride

Note: this stencil acts as a data wrapper, the pixel data is not locally copied

Returns: error if any

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◆ gf_evg_stencil_set_palette()

GF_Err gf_evg_stencil_set_palette	(	GF_EVGStencil *	stencil,
		const u8 *	palette,
		u32	pix_fmt,
		u32	nb_cols
	)

sets texture palette, only for greyscale textures.

Parameters

stencil	the target stencil
palette	palette data
pix_fmt	palette pixel format, must be RGB/BGR or any RGBA format
nb_cols	number of colors in palette

Returns: error if any

◆ gf_evg_stencil_set_texture_parametric()

GF_Err gf_evg_stencil_set_texture_parametric	(	GF_EVGStencil *	stencil,
		u32	width,
		u32	height,
		GF_PixelFormat	pixelFormat,
		gf_evg_texture_callback	callback,
		void *	cbk_udta,
		Bool	use_screen_coords
	)

sets parametric callback on a texture stencil. A parametric texture gets its pixel values from a callback function, the resulting value being blended according to the antialiasing level of the pixel. This allows creating rather complex custom textures, in a fashion similar to fragment shaders.

Parameters

stencil	the target stencil
width	texture width in pixels
height	texture height in pixels
pixelFormat	texture pixel format, indicates if the returned values are in RGB or YUV
callback	the callback function to use
cbk_udta	user data to pass to the callback function
use_screen_coords	if set, the coordinates passed to the callback function are screen coordinates rather than texture coordinates

Returns: error if any

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◆ gf_evg_stencil_set_mapping()

GF_Err gf_evg_stencil_set_mapping	(	GF_EVGStencil *	stencil,
		GF_TextureMapFlags	map_mode
	)

sets texture mapping options for a texture stencil

Parameters

stencil	the target stencil
map_mode	texture mapping flags to set

Returns: error if any

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◆ gf_evg_stencil_set_pad_color()

GF_Err gf_evg_stencil_set_pad_color	(	GF_EVGStencil *	stencil,
		GF_Color	pad_color
	)

sets padding color in RGBA If texture repeat is disabled and pad color is set, this color is used when outside of image, otherwise pixel is fetch from image border

Parameters

stencil	the target stencil
pad_color	color to use , 0 disables color padding

Returns: error if any

◆ gf_evg_stencil_get_pad_color()

u32 gf_evg_stencil_get_pad_color ( GF_EVGStencil * stencil )

gets padding color in RGBA

Parameters

stencil the target stencil

Returns: color used , 0 if error

◆ gf_evg_stencil_set_filter()

GF_Err gf_evg_stencil_set_filter	(	GF_EVGStencil *	stencil,
		GF_TextureFilter	filter_mode
	)

sets filtering mode for a texture stencil

Parameters

stencil	the target stencil
filter_mode	texture filtering mode to set

Returns: error if any

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◆ gf_evg_stencil_set_color_matrix()

GF_Err gf_evg_stencil_set_color_matrix	(	GF_EVGStencil *	stencil,
		GF_ColorMatrix *	cmat
	)

sets color matrix of a stencil

Parameters

stencil	the target stencil
cmat	the color matrix to use. If NULL, resets current color matrix

Returns: error if any

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◆ gf_evg_stencil_get_color_matrix()

GF_Err gf_evg_stencil_get_color_matrix	(	GF_EVGStencil *	stencil,
		GF_ColorMatrix *	cmat
	)

gets color matrix of a stencil

Parameters

stencil	the target stencil
cmat	filled with current color matrix of stencil

Returns: error if any

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◆ gf_evg_stencil_get_pixel()

u32 gf_evg_stencil_get_pixel	(	GF_EVGStencil *	stencil,
		s32	x,
		s32	y
	)

gets pixel at given position in ARGB format

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: pixel value

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◆ gf_evg_stencil_get_pixel_yuv()

u32 gf_evg_stencil_get_pixel_yuv	(	GF_EVGStencil *	stencil,
		s32	x,
		s32	y
	)

gets pixel at given position in AYUV format

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: pixel value

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◆ gf_evg_stencil_get_pixel_wide()

u64 gf_evg_stencil_get_pixel_wide	(	GF_EVGStencil *	stencil,
		s32	x,
		s32	y
	)

gets pixel at given position in ARGB format for more than 8 bits textures

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: pixel value

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◆ gf_evg_stencil_get_pixel_yuv_wide()

u64 gf_evg_stencil_get_pixel_yuv_wide	(	GF_EVGStencil *	stencil,
		s32	x,
		s32	y
	)

gets pixel at given position in AYUV format for more than 8 bits textures

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: pixel value

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◆ gf_evg_stencil_get_pixel_f()

GF_Vec4 gf_evg_stencil_get_pixel_f	(	GF_EVGStencil *	stencil,
		Float	x,
		Float	y
	)

gets ARGB pixel at a given position The position is given as normalize coordinates (between 0.0 and 1.0), {0.0,0.0} is top-left, {1.0,1.0} is bottom-right

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: output r, r, g, a components

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◆ gf_evg_stencil_get_pixel_yuv_f()

GF_Vec4 gf_evg_stencil_get_pixel_yuv_f	(	GF_EVGStencil *	stencil,
		Float	x,
		Float	y
	)

gets AYUV pixel at a given position The position is given as normalize coordinates (between 0.0 and 1.0), {0.0,0.0} is top-left, {1.0,1.0} is bottom-right

Parameters

stencil	the target stencil
x	horizontal coord
y	vertical coord

Returns: output y, u, v, a components

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◆ gf_evg_surface_new()

GF_EVGSurface* gf_evg_surface_new ( Bool center_coords )

creates a canvas surface object

Parameters

center_coords if GF_TRUE, indicates mathematical-like coord system (0,0) at the center of the canvas, otherwise indicates computer-like coord system (0,0) top-left corner

Returns: a new surface

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◆ gf_evg_surface_delete()

void gf_evg_surface_delete ( GF_EVGSurface * surf )

deletes a surface object

Parameters

surf	the surface object

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◆ gf_evg_enable_threading()

GF_Err gf_evg_enable_threading	(	GF_EVGSurface *	surf,
		s32	nb_threads
	)

enables threading on a canvas surface object (can only be called once per surface)

Parameters

surf	the target surface
nb_threads	number of additional threads to use for rendering. -1 use all availables core

Returns: error if any, GF_BAD_PARAM if threading was already allocated, GF_IO_ERR if only one core available and nb_threads not assigned to a positive value

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◆ gf_evg_surface_attach_to_texture()

GF_Err gf_evg_surface_attach_to_texture	(	GF_EVGSurface *	surf,
		GF_EVGStencil *	sten
	)

attaches a surface object to a texture stencil object

Parameters

surf	the surface object
sten	the stencil object (shll be a texture stencil)

Returns: error if any

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◆ gf_evg_surface_format_ok()

Bool gf_evg_surface_format_ok ( GF_PixelFormat pixelFormat )

checks if pixel format is supported for a surface

Parameters

pixelFormat the target pixel format

Returns: GF_TRUE if supported, GF_FALSE otherwise

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◆ gf_evg_surface_attach_to_buffer()

GF_Err gf_evg_surface_attach_to_buffer	(	GF_EVGSurface *	surf,
		u8 *	pixels,
		u32	width,
		u32	height,
		s32	pitch_x,
		s32	pitch_y,
		GF_PixelFormat	pixelFormat
	)

attaches a surface object to a memory buffer

Parameters

surf	the surface object
pixels	texture data
width	texture width in pixels
height	texture height in pixels
pitch_x	texture horizontal pitch (bytes to skip to get to next pixel). O means linear frame buffer (eg pitch_x==bytes per pixel)
pitch_y	texture vertical pitch (bytes to skip to get to next line)
pixelFormat	texture pixel format

Returns: error if any

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◆ gf_evg_surface_set_raster_level()

GF_Err gf_evg_surface_set_raster_level	(	GF_EVGSurface *	surf,
		GF_RasterQuality	level
	)

sets rasterizer precision

Parameters

surf	the surface object
level	the raster quality level

Returns: error if any

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◆ gf_evg_surface_get_raster_level()

GF_RasterQuality gf_evg_surface_get_raster_level ( GF_EVGSurface * surf )

gets rasterizer precision

Parameters

surf	the surface object

Returns: the raster quality level

◆ gf_evg_surface_force_aa()

GF_Err gf_evg_surface_force_aa ( GF_EVGSurface * surf )

Force next path fill to use antialias, reset at each gf_evg_surface_set_path

Parameters

surf	the surface object

Returns: error if any

◆ gf_evg_surface_set_matrix()

GF_Err gf_evg_surface_set_matrix	(	GF_EVGSurface *	surf,
		GF_Matrix2D *	mat
	)

sets the given matrix as the current transformations for all drawn paths

Note: this is only used for 2D rasterizer, and ignored in 3D mode

Parameters

surf	the surface object
mat	the matrix to set; if NULL, resets the current transformation

Returns: error if any

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◆ gf_evg_surface_set_matrix_3d()

GF_Err gf_evg_surface_set_matrix_3d	(	GF_EVGSurface *	surf,
		GF_Matrix *	mat
	)

sets the given matrix as the current transformations for all drawn paths. The matrix shall be a projection matrix (ortho or perspective) with normalized coordinates in [-1,1]. It may also contain a modelview part.

Perspective correct mapping is supported for textures and gradients:

the bottom-left corner of the path bounds is texture coordinate 0,0
the top-right corner of the path bounds is texture coordinate 1,1

Warning: When 3D matrices are used, filling a path shall be done with a stencil in auto matrix mode.

Note: this is only used for 2D rasterizer, and ignored in 3D mode

Parameters

surf	the surface object
mat	the matrix to set; if NULL, resets the current transformation

Returns: error if any

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◆ gf_evg_surface_set_clipper()

GF_Err gf_evg_surface_set_clipper	(	GF_EVGSurface *	surf,
		GF_IRect *	rc
	)

sets the given rectangle as a clipper When a clipper is enabled, nothing is drawn outside of the clipper. The clipper is not affected by the surface matrix

Parameters

surf	the surface object
rc	the clipper to set, in pixel coordinates of the surface; if NULL, disables clipper

Returns: error if any

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◆ gf_evg_surface_use_clipper()

Bool gf_evg_surface_use_clipper ( GF_EVGSurface * surf )

checks if clipper is active

Parameters

surf	the surface object

Returns: GF_TRUE if clipper is active, GF_FALSE otherwise

◆ gf_evg_surface_set_path()

GF_Err gf_evg_surface_set_path	(	GF_EVGSurface *	surf,
		GF_Path *	path
	)

sets the given path as the current one for drawing

Warning: This will internally copy the path after transformation with the current transfom. Changing the surface transform will have no effect unless calling this function again. The clipper and stencil mode may be changed at will

Note: this is only used for 2D rasterizer, and ignored in 3D mode

Parameters

surf	the surface object
path	the target path to rasterize

Returns: error if any

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◆ gf_evg_surface_fill()

GF_Err gf_evg_surface_fill	(	GF_EVGSurface *	surf,
		GF_EVGStencil *	stencil
	)

draw (filling) the current path on a surface using the given stencil and current clipper if any. If the stencil is a solid brush and its alpha value is 0, the surface is cleared if it has an alpha component, otherwise the call is ignored.

Note: this can be called several times with the same current path; this is only used for 2D rasterizer, and ignored in 3D mode

Parameters

surf	the surface object
stencil	the stencil to use to fill a path, if NULL uses 2D shader if setup

Returns: error if any

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◆ gf_evg_surface_multi_fill()

GF_Err gf_evg_surface_multi_fill	(	GF_EVGSurface *	surf,
		GF_EVGMultiTextureMode	operand,
		GF_EVGStencil *	sten1,
		GF_EVGStencil *	sten2,
		GF_EVGStencil *	sten3,
		Float	params[4]
	)

draw (filling) the current path on a surface using a compinaison of stencils and current clipper if any.

Parameters

surf	the surface object
operand	stencil combine effect
sten1	the first stencil to use, if NULL assumes shader and ignores operand
sten2	the second stencil to use, may be NULL depending on operand
sten3	the third stencil to use, may be NULL depending on operand
params	the parameters to control the operand

Returns: error if any

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◆ gf_evg_surface_clear()

GF_Err gf_evg_surface_clear	(	GF_EVGSurface *	surf,
		GF_IRect *	rc,
		GF_Color	col
	)

clears given pixel rectangle on a surface with the given color

Warning: this ignores any clipper set on the surface

Parameters

surf	the surface object
rc	the rectangle in pixel coordinates to clear. This may lay outside the surface, and shall not be NULL
col	the color used to clear the canvas. The alpha component is discarded if the surface does not have alpha, otherwise it is used

Returns: error if any

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◆ gf_evg_surface_set_center_coords()

void gf_evg_surface_set_center_coords	(	GF_EVGSurface *	surf,
		Bool	center_coords
	)

sets center coord mode of a surface

Note: this is only used for 2D rasterizer, and ignored in 3D mode

Parameters

surf	the surface object
center_coords	if GF_TRUE, indicates mathematical-like coord system (0,0) at the center of the canvas, otherwise indicates computer-like coord system (0,0) top-left corner

◆ gf_evg_surface_set_composite_mode()

void gf_evg_surface_set_composite_mode	(	GF_EVGSurface *	surf,
		GF_EVGCompositeMode	comp_mode
	)

sets surface composite mode, as defined in Canvas2D - only used for ARGB surfaces

Warning: this is still experimental

Parameters

surf	the surface object
comp_mode	the composition mode to use

◆ gf_evg_surface_set_alpha_callback()

void gf_evg_surface_set_alpha_callback	(	GF_EVGSurface *	surf,
		gf_evg_get_alpha	get_alpha,
		void *	cbk
	)

sets alpha callback function. This allows finer control over the blending, but does not allow for pixel color modification

Parameters

surf	the surface object
get_alpha	the callback function to alter the alpha value
cbk	opaque data for the callback function

◆ gf_evg_surface_enable_3d()

GF_Err gf_evg_surface_enable_3d ( GF_EVGSurface * surf )

enables 3D software rasterizer for surface

Parameters

surf	the target 3D surface

Returns: error if any

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◆ gf_evg_surface_set_projection()

GF_Err gf_evg_surface_set_projection	(	GF_EVGSurface *	surf,
		GF_Matrix *	mx
	)

sets projection matrix

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
mx	the target projection matrix

Returns: error if any

◆ gf_evg_surface_set_modelview()

GF_Err gf_evg_surface_set_modelview	(	GF_EVGSurface *	surf,
		GF_Matrix *	mx
	)

sets modelview matrix

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
mx	the target modelview matrix

Returns: error if any

◆ gf_evg_surface_draw_array()

GF_Err gf_evg_surface_draw_array	(	GF_EVGSurface *	surf,
		u32 *	indices,
		u32	nb_indices,
		Float *	vertices,
		u32	nb_vertices,
		u32	nb_comp,
		GF_EVGPrimitiveType	prim_type
	)

draws a set of primitive using vertices and an index buffer modelview matrix

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
indices	the array of indices to use in the vertex buffer
nb_indices	the number of indices
vertices	the array of vertices to use
nb_vertices	the number of vertices
nb_comp	the number of component per vertices (eg, 2, 3)
prim_type	the primitive type to use

Returns: error if any

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◆ gf_evg_surface_clear_depth()

GF_Err gf_evg_surface_clear_depth	(	GF_EVGSurface *	surf,
		Float	depth
	)

clears the depth buffer

Note: the depth buffer is set by the caller. If no depth buffer is assigned, this function returns GF_OK; the color buffer is cleared using gf_evg_surface_clear; this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
depth	the depth value to use

Returns: error if any

◆ gf_evg_surface_viewport()

GF_Err gf_evg_surface_viewport	(	GF_EVGSurface *	surf,
		u32	x,
		u32	y,
		u32	w,
		u32	h
	)

sets the surface viewport to convert from projected coordiantes to screen coordinates

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
x	the top-left coordinate of the viewport in pixels
y	the top-left coordinate of the viewport in pixels
w	the width of the viewport in pixels
h	the height of the viewport in pixels

Returns: error if any

◆ gf_evg_surface_draw_path()

GF_Err gf_evg_surface_draw_path	(	GF_EVGSurface *	surf,
		GF_Path *	path,
		Float	z
	)

draws path on a 3D surface with the given z.

The vertex shader is ignored (surface matrix must be set), and the fragment shader is called using perspective interpolation weights derived from the path bounds, using path bounds (top-left, top-right, bottom-right) vertices.

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
path	the path to draw
z	the z value to assign to the path in local coordinate system

Returns: error if any

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◆ gf_evg_set_depth_test()

GF_Err gf_evg_set_depth_test	(	GF_EVGSurface *	surf,
		GF_EVGDepthTest	mode
	)

sets depth buffer test

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
mode	the desired depth test mode

Returns: error if any

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◆ gf_evg_surface_set_fragment_shader()

GF_Err gf_evg_surface_set_fragment_shader	(	GF_EVGSurface *	surf,
		gf_evg_fragment_shader	shader,
		gf_evg_fragment_shader_init	shader_init,
		void *	shader_udta
	)

assigns fragment shader to the rasterizer.

Warning: If multithread is enabled, the shader must be thread-safe This can be used for 3D and 2D modes. In 2D mode, texture coordinates are derived from path bounds

Parameters

surf	the target 3D surface
shader	the fragment shader callback to use
shader_init	the fragment shader init callback to use
shader_udta	opaque data to pass to the callback function

Returns: error if any

◆ gf_evg_surface_set_vertex_shader()

GF_Err gf_evg_surface_set_vertex_shader	(	GF_EVGSurface *	surf,
		gf_evg_vertex_shader	shader,
		void *	shader_udta
	)

assigns vertex shader to the rasterizer

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
shader	the vertex shader callback to use
shader_udta	opaque data to pass to the callback function

Returns: error if any

◆ gf_evg_surface_set_ccw()

GF_Err gf_evg_surface_set_ccw	(	GF_EVGSurface *	surf,
		Bool	is_ccw
	)

sets face orientation for the primitives

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
is_ccw	if GF_TRUE, face are given in counter-clockwise order, otherwise in clockwise order

Returns: error if any

◆ gf_evg_surface_set_backcull()

GF_Err gf_evg_surface_set_backcull	(	GF_EVGSurface *	surf,
		Bool	backcull
	)

enables/disables backface culling

Warning: not enabling backface culling when anti-aliasing is on may result in visual artefacts

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
backcull	if GF_TRUE, faces with normals poiting away from camera will not be drawn

Returns: error if any

◆ gf_evg_surface_set_antialias()

GF_Err gf_evg_surface_set_antialias	(	GF_EVGSurface *	surf,
		Bool	antialias
	)

enables/disables anti-aliased rendering

Warning: not enabling backface culling when anti-aliasing is on may result in visual artefacts

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
antialias	if GF_TRUE, edges will be anti-aliased

Returns: error if any

◆ gf_evg_surface_set_min_depth()

GF_Err gf_evg_surface_set_min_depth	(	GF_EVGSurface *	surf,
		Float	min_depth
	)

sets minimum depth value for coordinates normalization - see OpenGL glDepthRange

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
min_depth	the minimum depth value

Returns: error if any

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◆ gf_evg_surface_set_max_depth()

GF_Err gf_evg_surface_set_max_depth	(	GF_EVGSurface *	surf,
		Float	max_depth
	)

sets maximum depth value for coordinates normalization - see OpenGL glDepthRange

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
max_depth	the maximum depth value

Returns: error if any

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◆ gf_evg_surface_set_clip_zero()

GF_Err gf_evg_surface_set_clip_zero	(	GF_EVGSurface *	surf,
		Bool	clip_zero
	)

indicates that the clip space after projection is [0,1] and not [-1, 1]

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
clip_zero	if GF_TRUE, the projected vertices depth are in [0, 1], otherwise in [-1, 1]

Returns: error if any

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◆ gf_evg_surface_set_point_size()

GF_Err gf_evg_surface_set_point_size	(	GF_EVGSurface *	surf,
		Float	size
	)

sets point size value for points primitives

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
size	the desired point size in pixels

Returns: error if any

◆ gf_evg_surface_set_line_size()

GF_Err gf_evg_surface_set_line_size	(	GF_EVGSurface *	surf,
		Float	size
	)

sets line size (width) value for points primitives

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
size	the desired line size in pixels

Returns: error if any

◆ gf_evg_surface_set_point_smooth()

GF_Err gf_evg_surface_set_point_smooth	(	GF_EVGSurface *	surf,
		Bool	smooth
	)

enables point smoothing. When point smoothing is enabled, the geometry drawn is a circle, otherwise a square

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
smooth	if GF_TRUE, point smoothing is enabled

Returns: error if any

◆ gf_evg_surface_disable_early_depth()

GF_Err gf_evg_surface_disable_early_depth	(	GF_EVGSurface *	surf,
		Bool	disable
	)

disables early depth test If your fragment shader modifies the depth of the fragment, you must call this function to avoid early depth test (fragment discarded before calling the shader)

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
disable	if GF_TRUE, early depth test is disabled

Returns: error if any

◆ gf_evg_surface_write_depth()

GF_Err gf_evg_surface_write_depth	(	GF_EVGSurface *	surf,
		Bool	do_write
	)

disables depth buffer write

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
do_write	if GF_TRUE, depth values are written to the depth buffer (default when creating the rasterizer)

Returns: error if any

◆ gf_evg_surface_set_depth_buffer()

GF_Err gf_evg_surface_set_depth_buffer	(	GF_EVGSurface *	surf,
		Float *	depth
	)

sets depth buffer The 3D rasterizer does not allocate any surface (depth or color buffers), it is the user responsibility to set these buffers

Warning: do NOT forget to resize your depth buffer when resizing the canvas !

Note: this is only used for 3D rasterizer, and fails 2D mode

Parameters

surf	the target 3D surface
depth	the depth buffer to use. Its size shall be Floatwidthheight

Returns: error if any

◆ gf_gf_evg_rgb_to_yuv_f()

GF_Err gf_gf_evg_rgb_to_yuv_f	(	GF_EVGSurface *	surf,
		Float	r,
		Float	g,
		Float	b,
		Float *	y,
		Float *	cb,
		Float *	cr
	)

performs RGB to YUV conversion

Parameters

surf	the target surface
r	the source red component
g	the source green component
b	the source blue component
y	the output Y component
cb	the output U/Cb component
cr	the output V/Cr component

Returns: error if any

◆ gf_evg_yuv_to_rgb_f()

GF_Err gf_evg_yuv_to_rgb_f	(	GF_EVGSurface *	surf,
		Float	y,
		Float	cb,
		Float	cr,
		Float *	r,
		Float *	g,
		Float *	b
	)

performs YUV to RGB conversion

Parameters

surf	the target surface
y	the source Y component
cb	the source U/Cb component
cr	the source V/Cr component
r	the output red component
g	the output green component
b	the output blue component

Returns: error if any

◆ gf_evg_rgb_to_yuv()

void gf_evg_rgb_to_yuv	(	GF_EVGSurface *	surf,
		GF_Color	col,
		u8 *	y,
		u8 *	cb,
		u8 *	cr
	)

converts RGB to YUV

Parameters

surf	the target surface
col	the source RGBA color
y	the output Y value
cb	the output Cb/U value
cr	the output Cr/V value

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◆ gf_evg_argb_to_ayuv()

GF_Color gf_evg_argb_to_ayuv	(	GF_EVGSurface *	surf,
		GF_Color	col
	)

converts ARGB to AYUV

Parameters

surf	the target surface
col	the source ARGB color

Returns: the result AYUV color

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◆ gf_evg_ayuv_to_argb()

GF_Color gf_evg_ayuv_to_argb	(	GF_EVGSurface *	surf,
		GF_Color	col
	)

converts AYUV to ARGB

Parameters

surf	the target surface
col	the source AYUV color

Returns: the result ARGB color

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◆ gf_evg_argb_to_ayuv_wide()

u64 gf_evg_argb_to_ayuv_wide	(	GF_EVGSurface *	surf,
		u64	col
	)

converts ARGB to AYUV for wide colors

Parameters

surf	the target surface
col	the source ARGB color

Returns: the result AYUV color

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◆ gf_evg_ayuv_to_argb_wide()

u64 gf_evg_ayuv_to_argb_wide	(	GF_EVGSurface *	surf,
		u64	col
	)

converts AYUV to ARGB for wide color

Parameters

surf	the target surface
col	the source AYUV color

Returns: the result ARGB color

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◆ gf_evg_surface_set_mask_mode()

GF_Err gf_evg_surface_set_mask_mode	(	GF_EVGSurface *	surf,
		GF_EVGMaskMode	mask_mode
	)

sets global alpha mask mode

The global alpha mask is an 8-bit alpha channel the size of the surface. Any resize operation on the surface will reset the alpha mask Typcial usage for the alpha mask is to setup the surface, use GF_EVGMASK_DRAW to draw your mask then GF_EVGMASK_USE to apply the mask on your draw calls

Whenever the mask mode is changed to GF_EVGMASK_DRAW, the alpha masked is cleared

Parameters

surf	the target surface
mask_mode	the current mask mode

Returns: error if any

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◆ gf_evg_surface_get_mask_mode()

GF_EVGMaskMode gf_evg_surface_get_mask_mode ( GF_EVGSurface * surf )

gets global alpha mask mode

Parameters

surf	the target surface

Returns: the current mask mode

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Data Structures

Typedefs

Enumerations

Functions

Detailed Description

Data Structure Documentation

◆ GF_EVGFragmentParam

◆ GF_EVGVertexParam

Typedef Documentation

◆ gf_evg_texture_callback

◆ gf_evg_get_alpha

◆ gf_evg_fragment_shader

◆ gf_evg_fragment_shader_init

◆ gf_evg_vertex_shader

Enumeration Type Documentation

◆ GF_StencilType

◆ GF_GradientMode

◆ GF_TextureMapFlags

◆ GF_TextureFilter

◆ GF_RasterQuality

◆ GF_EVGMultiTextureMode

◆ GF_EVGCompositeMode

◆ GF_EVGPrimitiveType

◆ GF_EVGDepthTest

◆ GF_EVGFragmentType

◆ GF_EVGMaskMode

Function Documentation

◆ gf_evg_stencil_new()

◆ gf_evg_stencil_delete()

◆ gf_evg_stencil_set_matrix()

◆ gf_evg_stencil_get_matrix()

◆ gf_evg_stencil_set_auto_matrix()

◆ gf_evg_stencil_get_auto_matrix()

◆ gf_evg_stencil_type()

◆ gf_evg_stencil_set_brush_color()

◆ gf_evg_stencil_get_brush_color()

◆ gf_evg_stencil_set_gradient_mode()

◆ gf_evg_stencil_set_linear_gradient()

◆ gf_evg_stencil_set_radial_gradient()

◆ gf_evg_stencil_set_gradient_interpolation()

◆ gf_evg_stencil_push_gradient_interpolation()

◆ gf_evg_stencil_set_alpha()

◆ gf_evg_stencil_get_alpha()

◆ gf_evg_texture_format_ok()

◆ gf_evg_stencil_set_texture()

◆ gf_evg_stencil_set_texture_planes()

◆ gf_evg_stencil_set_palette()

◆ gf_evg_stencil_set_texture_parametric()

◆ gf_evg_stencil_set_mapping()

◆ gf_evg_stencil_set_pad_color()

◆ gf_evg_stencil_get_pad_color()

◆ gf_evg_stencil_set_filter()

◆ gf_evg_stencil_set_color_matrix()

◆ gf_evg_stencil_get_color_matrix()

◆ gf_evg_stencil_get_pixel()

◆ gf_evg_stencil_get_pixel_yuv()

◆ gf_evg_stencil_get_pixel_wide()

◆ gf_evg_stencil_get_pixel_yuv_wide()

◆ gf_evg_stencil_get_pixel_f()

◆ gf_evg_stencil_get_pixel_yuv_f()

◆ gf_evg_surface_new()

◆ gf_evg_surface_delete()

◆ gf_evg_enable_threading()

◆ gf_evg_surface_attach_to_texture()

◆ gf_evg_surface_format_ok()

◆ gf_evg_surface_attach_to_buffer()

◆ gf_evg_surface_set_raster_level()

◆ gf_evg_surface_get_raster_level()

◆ gf_evg_surface_force_aa()

◆ gf_evg_surface_set_matrix()

◆ gf_evg_surface_set_matrix_3d()

◆ gf_evg_surface_set_clipper()

◆ gf_evg_surface_use_clipper()

◆ gf_evg_surface_set_path()

◆ gf_evg_surface_fill()

◆ gf_evg_surface_multi_fill()

◆ gf_evg_surface_clear()

◆ gf_evg_surface_set_center_coords()

◆ gf_evg_surface_set_composite_mode()

◆ gf_evg_surface_set_alpha_callback()