pandory500/SDL-mirror
2
0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

My first OpenGL shader! Momma will be so proud!

Browse source 
This shader implements the software renderer mask semantics where the source pixel is multiplied by the color and alpha modulation values and then any pixel with non-zero alpha is fully opaque.

The OpenGL renderer on Mac OS X now passes all the automated render tests! :)

--HG--
extra : convert_revision : svn%3Ac70aab31-4412-0410-b14c-859654838e24/trunk%404209
This commit is contained in:
Sam Lantinga 2009-11-21 05:29:31 +00:00
parent 22c1e66180
commit 335b459777
1 changed files with 53 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

58
src/video/SDL_renderer_gl.c
View file

@ -175,6 +175,7 @@ typedef struct
PFNGLPROGRAMSTRINGARBPROC glProgramStringARB;
/* (optional) fragment programs */
GLuint fragment_program_mask;
GLuint fragment_program_UYVY;
} GL_RenderData;
@ -484,6 +485,17 @@ power_of_2(int input)
//#define DEBUG_PROGRAM_COMPILE 1
static void
set_shader_error(GL_RenderData * data, const char *prefix)
{
GLint pos = 0;
const GLubyte *errstr;
data->glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &pos);
errstr = data->glGetString(GL_PROGRAM_ERROR_STRING_ARB);
printf("%s: shader compile error at position %d: %s",
prefix, (int) pos, (const char *) errstr);
}
static GLuint
compile_shader(GL_RenderData * data, GLenum shader_type, const char *_code)
{
@ -541,6 +553,18 @@ compile_shader(GL_RenderData * data, GLenum shader_type, const char *_code)
}
/*
* Fragment program that implements mask semantics
*/
static const char *fragment_program_mask_source_code = "!!ARBfp1.0\n"
"OUTPUT output = result.color;\n"
"TEMP value;\n"
"TEX value, fragment.texcoord[0], texture[0], %TEXTURETARGET%;\n"
"MUL value, fragment.color, value;\n"
"SGE value.a, value.a, 0.001;\n"
"MOV output, value;\n"
"END";
/*
* Fragment program that renders from UYVY textures.
* The UYVY to RGB equasion is:
@ -751,7 +775,7 @@ GL_CreateTexture(SDL_Renderer * renderer, SDL_Texture * texture)
compile_shader(renderdata, GL_FRAGMENT_PROGRAM_ARB,
fragment_program_UYVY_source_code);
if (renderdata->fragment_program_UYVY == 0) {
SDL_SetError("Fragment program compile error");
set_shader_error(renderdata, "UYVY");
return -1;
}
}
@ -1162,6 +1186,7 @@ GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
{
GL_RenderData *data = (GL_RenderData *) renderer->driverdata;
GL_TextureData *texturedata = (GL_TextureData *) texture->driverdata;
GLuint shader = 0;
int minx, miny, maxx, maxy;
GLfloat minu, maxu, minv, maxv;
@ -1215,6 +1240,23 @@ GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
GL_SetBlendMode(data, texture->blendMode, 0);
/* Set up the shader for the copy, we have a special one for MASK */
shader = texturedata->shader;
if (texture->blendMode == SDL_BLENDMODE_MASK && !shader) {
if (data->fragment_program_mask == 0) {
data->fragment_program_mask =
compile_shader(data, GL_FRAGMENT_PROGRAM_ARB,
fragment_program_mask_source_code);
if (data->fragment_program_mask == 0) {
/* That's okay, we'll just miss some of the blend semantics */
data->fragment_program_mask = ~0;
}
}
if (data->fragment_program_mask != ~0) {
shader = data->fragment_program_mask;
}
}
if (texture->scaleMode != data->scaleMode) {
switch (texture->scaleMode) {
case SDL_TEXTURESCALEMODE_NONE:
@ -1235,9 +1277,9 @@ GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
data->scaleMode = texture->scaleMode;
}
if (texturedata->shader != 0) {
if (shader) {
data->glEnable(GL_FRAGMENT_PROGRAM_ARB);
data->glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, texturedata->shader);
data->glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, shader);
}
data->glBegin(GL_TRIANGLE_STRIP);
@ -1251,7 +1293,7 @@ GL_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
data->glVertex2f(0.5f + maxx, 0.5f + maxy);
data->glEnd();
if (texturedata->shader != 0) {
if (shader) {
data->glDisable(GL_FRAGMENT_PROGRAM_ARB);
}
@ -1377,7 +1419,13 @@ GL_DestroyRenderer(SDL_Renderer * renderer)
if (data->GL_ARB_fragment_program_supported) {
data->glDisable(GL_FRAGMENT_PROGRAM_ARB);
data->glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, 0);
if (data->fragment_program_UYVY != 0) {
if (data->fragment_program_mask &&
data->fragment_program_mask != ~0) {
data->glDeleteProgramsARB(1,
&data->fragment_program_mask);
}
if (data->fragment_program_UYVY &&
data->fragment_program_UYVY != ~0) {
data->glDeleteProgramsARB(1,
&data->fragment_program_UYVY);
}