Mercurial > sdl-ios-xcode
diff src/video/SDL_renderer_gl.c @ 2846:3d7833d5a4be
Slight optimization of the shader, no need to scale into 0..255
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sun, 07 Dec 2008 04:38:32 +0000 |
parents | 1cc5d5b164e2 |
children | 7d020441fa81 |
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--- a/src/video/SDL_renderer_gl.c Sun Dec 07 04:02:23 2008 +0000 +++ b/src/video/SDL_renderer_gl.c Sun Dec 07 04:38:32 2008 +0000 @@ -380,12 +380,14 @@ } --info->num_texture_formats; } +/* if (SDL_GL_ExtensionSupported("GL_APPLE_ycbcr_422")) { data->GL_APPLE_ycbcr_422_supported = SDL_TRUE; } if (SDL_GL_ExtensionSupported("GL_MESA_ycbcr_texture")) { data->GL_MESA_ycbcr_texture_supported = SDL_TRUE; } +*/ if (SDL_GL_ExtensionSupported("GL_APPLE_texture_range")) { data->glTextureRangeAPPLE = (void (*)(GLenum, GLsizei, const GLvoid *)) @@ -515,7 +517,7 @@ // Byte layout is Cb, Y1, Cr, Y2. // 4 bytes == 2 pixels: Y1/Cb/Cr, Y2/Cb/Cr // !!! FIXME: this ignores blendmodes, etc. -// !!! FIXME: this could be more efficient...use a dot product for green, not convert to 255.0 range, etc. +// !!! FIXME: this could be more efficient...use a dot product for green, etc. static const char *fragment_program_UYVY_source_code = "!!ARBfp1.0\n" @@ -531,13 +533,12 @@ // halve the coordinates to grab the correct 32 bits for the fragment. "MUL work, fragment.texcoord, { 0.5, 1.0, 1.0, 1.0 };\n" - // Sample the YUV texture. Cb, Y1, Cr, Y2, are stored in r,g,b,a. + // Sample the YUV texture. Cb, Y1, Cr, Y2, are stored x,y,z,w // !!! FIXME: "RECT" needs to be "2D" if we're not using texture_rectangle extension. :/ "TEX uyvy, work, texture[0], RECT;\n" - // Scale from 0.0/1.0 to 0.0/255.0 and do subtractions. (!!! FIXME: optimize!) - "MUL uyvy, uyvy, { 255.0, 255.0, 255.0, 255.0 };\n" - "SUB uyvy, uyvy, { 128.0, 16.0, 128.0, 16.0 };\n" + // Do subtractions (128/255, 16/255, 128/255, 16/255) + "SUB uyvy, uyvy, { 0.501960784313726, 0.06274509803922, 0.501960784313726, 0.06274509803922 };\n" // Choose the luminance component by texcoord. // !!! FIXME: laziness wins out for now... just average Y1 and Y2. @@ -556,9 +557,6 @@ // Do final addition for Green channel. (!!! FIXME: this should be a DPH?) "ADD work.g, work.g, uyvy.w;\n" - // Scale back to 0.0/1.0. (this number is 1.0/255.0). - "MUL work, work, { 0.0039215686274509803, 0.0039215686274509803, 0.0039215686274509803, 0.0039215686274509803 };\n" - // Make sure alpha channel is fully opaque. (!!! FIXME: blend modes!) "MOV work.a, { 1.0 };\n"