// license:BSD-3-Clause // copyright-holders:Sven Gothel const char glsl_bilinear_rgb32_lut_fsh_src[] = "\n" "#pragma optimize (on)\n" "#pragma debug (off)\n" "\n" "uniform sampler2D color_texture;\n" "uniform sampler2D colortable_texture;\n" "uniform vec2 colortable_sz; // orig size\n" "uniform vec2 colortable_pow2_sz; // pow2 ct size\n" "uniform vec2 color_texture_pow2_sz; // pow2 tex size\n" "\n" "vec4 lutTex2D(in vec2 texcoord)\n" "{\n" " vec4 color_tex;\n" " vec2 color_map_coord;\n" " vec4 color0;\n" " float colortable_scale = (colortable_sz.x/3.0) / colortable_pow2_sz.x;\n" "\n" " // normalized texture coordinates ..\n" " color_tex = texture2D(color_texture, texcoord) * ((colortable_sz.x/3.0)-1.0)/colortable_pow2_sz.x;// lookup space \n" "\n" " color_map_coord.x = color_tex.b;\n" " color0.b = texture2D(colortable_texture, color_map_coord).b;\n" "\n" " color_map_coord.x = color_tex.g + colortable_scale;\n" " color0.g = texture2D(colortable_texture, color_map_coord).g;\n" "\n" " color_map_coord.x = color_tex.r + 2.0 * colortable_scale;\n" " color0.r = texture2D(colortable_texture, color_map_coord).r;\n" "\n" " return color0;\n" "}\n" "\n" "void main()\n" "{\n" " vec2 xy = gl_TexCoord[0].st;\n" "\n" " // mix(x,y,a): x*(1-a) + y*a\n" " //\n" " // bilinear filtering includes 2 mix:\n" " //\n" " // pix1 = tex[x0][y0] * ( 1 - u_ratio ) + tex[x1][y0] * u_ratio\n" " // pix2 = tex[x0][y1] * ( 1 - u_ratio ) + tex[x1][y1] * u_ratio\n" " // fin = pix1 * ( 1 - v_ratio ) + pix2 * v_ratio\n" " //\n" " // so we can use the build in mix function for these 2 computations ;-)\n" " //\n" " vec2 uv_ratio = fract(xy*color_texture_pow2_sz); // xy*color_texture_pow2_sz - floor(xy*color_texture_pow2_sz);\n" " vec2 one = 1.0/color_texture_pow2_sz;\n" "\n" " vec4 col1, col2;\n" "\n" " col1 = mix( lutTex2D(xy ), lutTex2D(xy + vec2(one.x, 0.0)), uv_ratio.x);\n" " col2 = mix( lutTex2D(xy + vec2(0.0, one.y)), lutTex2D(xy + one ), uv_ratio.x);\n" "\n" " gl_FragColor = mix ( col1, col2, uv_ratio.y );\n" "}\n" "\n" "\n" ;