GLSL Vertex Code

This group documents the GLSL functions fastuidraw makes available to GLSL code fragments for only vertex shading for custom shading as embodied by the classes fastuidraw::glsl::PainterItemShaderGLSL, fastuidraw::glsl::PainterBlendShaderGLSL and fastuidraw::glsl::PainterBrushShaderGLSL. More...

Functions
vec2	fastuidraw_align_normal_to_screen (in vec3 clip_p, in vec2 n)
float	fastuidraw_local_distance_from_pixel_distance (in float pixel_distance, in vec3 clip_p, in vec3 clip_direction)

Variables
mat3	fastuidraw_item_matrix

Detailed Description

This group documents the GLSL functions fastuidraw makes available to GLSL code fragments for only vertex shading for custom shading as embodied by the classes fastuidraw::glsl::PainterItemShaderGLSL, fastuidraw::glsl::PainterBlendShaderGLSL and fastuidraw::glsl::PainterBrushShaderGLSL.

Function Documentation

fastuidraw_align_normal_to_screen()

vec2 fastuidraw_align_normal_to_screen	(	in vec3	clip_p,
		in vec2	n
	)

Given a normal vector in local coordinate and a position in -clip- coordinates, return the vector N in local coordinates so that N transformed to screen coordiantes is perpindicular to the vector T transformed to screen coordinate where T is the vector perpindicular to the input normal vector. The magnitude of N is not necessarily the same as the magnitude of the input vector n, only the nature of its direction is guarnateed.

Parameters

clip_p	position in CLIP coordinates
n	normal vector in LOCAL coordinates

Definition at line 56 of file fastuidraw_align.vert.glsl.hpp.

fastuidraw_local_distance_from_pixel_distance()

float fastuidraw_local_distance_from_pixel_distance	(	in float	pixel_distance,
		in vec3	clip_p,
		in vec3	clip_direction
	)

Given a point (clip_p) and a direction (clip_direction) in clip-coordinates, compute the coeffecient W so that AFTER projection, the points clip_p and (clip_p + W * clip_direction) are pixel_distance pixels apart.

Parameters

pixel_distance	the distance in pixels to move by
clip_p	the position of the vertex in CLIP coordiantes
clip_direction	the direction by which to move in CLIP coordiantes

Definition at line 34 of file fastuidraw_compute_local_distance_from_pixel_distance.glsl.hpp.

Variable Documentation

fastuidraw_item_matrix

mat3 fastuidraw_item_matrix

Gives the 3x3 transformation matrix from local item coordiantes to clip-coordinates as clip_coordinates.xyz = fastuidraw_item_matrix * vec3(item_coordinates.xy, 1.0)

Definition at line 28 of file fastuidraw_painter_globals.vert.glsl.hpp.