// license:BSD-3-Clause // copyright-holders:Sven Gothel const char glsl_bilinear_idx16_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; // ct 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" "\n" " // normalized texture coordinates ..\n" " color_tex = texture2D(color_texture, texcoord);\n" "\n" " // GL_UNSIGNED_SHORT GL_ALPHA in ALPHA16 conversion:\n" " // general: f = c / ((2*N)-1), c color bitfield, N number of bits\n" " // ushort: c = ((2**16)-1)*f;\n" " color_map_coord.x = floor( 65535.0 * color_tex.a + 0.5 );\n" "\n" " // map it to the 2D lut table\n" " color_map_coord.y = floor(color_map_coord.x/colortable_sz.x);\n" " color_map_coord.x = mod(color_map_coord.x,colortable_sz.x);\n" "\n" " return texture2D(colortable_texture, (color_map_coord+vec2(0.5)) / colortable_pow2_sz);\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" ;