quakeforge/libs/video/renderer/glsl/quaketxt.vert
Bill Currie 151cc05882 Add support for vertex colors.
As I need to control the alpha, they're sent as rgba rather than quake
palette indices. Text works well. All other 2d stuff does not :(.
2011-12-28 09:04:26 +09:00

49 lines
1 KiB
GLSL

uniform mat4 mvp_mat;
/** Vertex position.
x, y, cx, cy
\a vertex provides the onscreen location at which to draw the character
(\a x, \a y) and which corner of the character cell this vertex
represents (\a cx, \a cy). \a cx and \a cy must be either 0 or 1, or
wierd things will happen with the character cell.
*/
attribute vec4 vertex;
/** Vectex color.
r, g, b, a
*/
attribute vec4 vcolor;
/** The character to draw.
The quake character map supports only 256 characters, 0-255. Any other
value will give interesting results.
*/
attribute float char;
/** Coordinate in character map texture.
*/
varying vec4 color;
varying vec2 st;
void
main (void)
{
float row, col;
vec2 pos, corner, uv;
const vec2 inset = vec2 (0.03125, 0.03125);
const vec2 size = vec2 (0.0625, 0.0625);
row = floor (char / 16.0);
col = mod (char, 16.0);
pos = vertex.xy;
corner = vertex.zw;
uv = vec2 (col, row) + inset * (1.0 - 2.0 * corner) + corner;
uv *= size;
gl_Position = mvp_mat * vec4 (pos + corner * 8.0, 0.0, 1.0);
st = uv;
color = vcolor;
}