#if SPECIAL
#include "main.h"
#endif

const char *GLShader_Levels = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec2 TexCoord;\n"
"uniform float Start;\n"
"uniform float Mid;\n"
"uniform float End;\n"
"uniform vec4 StartCol;\n"
"uniform vec4 MidCol;\n"
"uniform vec4 EndCol;\n"
"uniform sampler2D Texture;\n"
"void main()\n"
"{\n"
"vec4 OutCol = texture(Texture, TexCoord);\n"
// individual channels
"vec4 ColorI = pow(OutCol, MidCol);\n"
"vec4 ValI = 1.0f / (EndCol - StartCol) * (ColorI - StartCol);\n"
// global channel (doesn't affect alpha)
"vec4 ColorG = pow(ValI, vec4(Mid));\n"
"vec4 ValG = 1.0f / (End - Start) * (ColorG - Start);\n"
"ValG = vec4(ValG.rgb, ValI.a);\n"
"FragColor = clamp(ValG, 0.0f, 1.0f);\n"
"}\0";

const char *GLShader_SolidColor = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec2 TexCoord;\n"
"uniform vec4 Color;\n"
"uniform sampler2D Texture;\n"
"void main()\n"
"{\n"
"vec4 OutCol = texture(Texture, TexCoord);\n"
"FragColor = Color*OutCol;\n"
"}\0";

const char *GLShader_GaussianBlur = "#version 330 core\n"
"uniform float Radius;\n"
"uniform vec2 Direction;\n"
"uniform sampler2D Texture;\n"
"out vec4 FragColor;\n"
"in vec2 TexCoord;\n"
"\n"
"vec4 blur(sampler2D image, vec2 uv, vec2 resolution, vec2 direction) {\n"
"    vec4 color = vec4(0.0f);\n"
"    float Omega = Radius / 3;\n"
"    float Divisor = 2*Omega*Omega;\n"
"    float A2 = 1.0f / (Omega * sqrt(2*3.141592));\n"
"    for (float Span = -round(Radius); Span < round(Radius); Span++) {\n"
"        float Dividend = -Span * Span;\n"
"        float Multiplier =  A2 * exp(Dividend/Divisor);\n"
"        vec2 Dir = Span*direction;\n"
"        color += texture(image, uv + (Dir / resolution)) * Multiplier;\n"
"    }\n"
"    return color;\n"
"}\n"
"void main(void) {\n"
"    FragColor = blur(Texture, TexCoord, vec2(1280, 720),  Direction);\n"
"}\0";