path: root/gl_calls.cpp

#include "gl_calls.h"

const char *DefaultVertexShaderSource = "#version 330 core\n"
"layout (location = 0) in vec3 aPos;\n"
"layout (location = 1) in vec2 aTexCoord;\n"
"out vec2 TexCoord;\n"
"uniform int VertexMode;\n"
"uniform vec3 CompDimensions;\n"
"void main()\n"
"{\n"
" if (VertexMode == 0) {\n"
"   gl_Position = vec4(aPos, 1.0);\n"
"} else {\n"
"   gl_Position = vec4(vec2(aPos.x / CompDimensions.x, aPos.y / CompDimensions.y) * 2 - 1.0f, 0.0f, 1.0);\n"
"}\n"
" TexCoord = aTexCoord;\n"
"}\0";
const char *DefaultFragmentShaderSource = "#version 330 core\n"
"out vec4 FragColor;\n"
"in vec2 TexCoord;\n"
"uniform sampler2D Texture;\n"
"uniform int FragmentMode;\n"
"void main()\n"
"{\n"
"vec4 Col = texture(Texture, TexCoord);\n"
" if (FragmentMode == 0) {\n"
"   FragColor = Col;\n"
"} else {\n"
"   FragColor = vec4(vec3(1.0f), Col.a);\n"
"}\n"
"}\0";
const char *FragmentShaderEffectSource[] = {"",
"#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 ourTexture;\n"
"void main()\n"
"{\n"
"vec4 OutCol = texture(ourTexture, 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",
"#version 330 core\n"
"uniform float Radius;\n"
"uniform vec2 Direction;\n"
"uniform sampler2D ourTexture;\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 += texture2D(image, uv + (Dir / resolution)) * Multiplier;\n"
"    }\n"
"    return color;\n"
"}\n"
"void main(void) {\n"
"    gl_FragColor = blur(ourTexture, TexCoord, vec2(1280, 720),  Direction);\n"
"}\0"
};


// #include "effects_gl.cpp"

static void GL_InitDefaultShader() {
    DefaultVertexShader = glCreateShader(GL_VERTEX_SHADER);

    glShaderSource(DefaultVertexShader, 1, &DefaultVertexShaderSource, NULL);
    glCompileShader(DefaultVertexShader);

    int success;
    char infoLog[512];
    glGetShaderiv(DefaultVertexShader, GL_COMPILE_STATUS, &success);

    if(!success)
    {
        glGetShaderInfoLog(DefaultVertexShader, 512, NULL, infoLog);
        printf("Vertex shader fail:\n %s", infoLog);
    }

    uint32 DefaultFragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

    glShaderSource(DefaultFragmentShader, 1, &DefaultFragmentShaderSource, NULL);
    glCompileShader(DefaultFragmentShader);

    glGetShaderiv(DefaultFragmentShader, GL_COMPILE_STATUS, &success);

    if(!success)
    {
        glGetShaderInfoLog(DefaultFragmentShader, 512, NULL, infoLog);
        printf("Fragment shader fail:\n %s", infoLog);
    }

    // Shader programs link both types of shaders together.
    DefaultShaderProgram = glCreateProgram();

    glAttachShader(DefaultShaderProgram, DefaultVertexShader);
    glAttachShader(DefaultShaderProgram, DefaultFragmentShader);
    glLinkProgram(DefaultShaderProgram);

    glGetProgramiv(DefaultShaderProgram, GL_LINK_STATUS, &success);
    if(!success) {
        glGetProgramInfoLog(DefaultShaderProgram, 512, NULL, infoLog);
        printf("Shader linkage fail:\n %s", infoLog);
    }

    // Default vertex shader is still needed to link to other effects.
    glDeleteShader(DefaultFragmentShader);
}

static void GL_InitDefaultVerts() {

    unsigned int GLIndices[] = {
        0, 1, 3,
        1, 2, 3
    };

    // Indices!
    glGenVertexArrays(1, &DefaultVerts.VertexArrayObject);

    glGenBuffers(1, &DefaultVerts.ElementBufferObject);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, DefaultVerts.ElementBufferObject);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GLIndices), GLIndices,
                 GL_STATIC_DRAW);
    glGenBuffers(1, &DefaultVerts.VertexBufferObject);

    // Our vertices need to be stored in this buffer.
    glBindBuffer(GL_ARRAY_BUFFER, DefaultVerts.VertexBufferObject);
    glBufferData(GL_ARRAY_BUFFER, sizeof(GL_DefaultVertices), GL_DefaultVertices, GL_STATIC_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // texture coordinate (note the last parameter's offset)
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);
}

#if 0
void
GL_InitTexture(gl_effect_layer *Test)
{
    glGenFramebuffers(1, &Test->FramebufferObject);
    glGenTextures(1, &Test->Texture);
    glGenRenderbuffers(1, &Test->Color_Renderbuffer);
    glGenRenderbuffers(1, &Test->Stencil_Renderbuffer);
    Test->Initialized = true;
}

void
GL_UpdateTexture(gl_effect_layer *Test, void *Data, uint16 Width, uint16 Height, bool32 Multisample)
{
    glViewport(0, 0, Width, Height);

    if (!Test->Initialized) {
        GL_InitTexture(Test);
    }

    GLenum Target = GL_TEXTURE_2D;
    if (Multisample)
        Target = GL_TEXTURE_2D_MULTISAMPLE;

    glBindTexture(Target, Test->Texture);

    if (Multisample) {
        // glTexImage2DMultisample(GL_TEXTURE_2D_MULTISAMPLE, 4, GL_RGB, Width, Height, GL_TRUE);
        glBindTexture(GL_TEXTURE_2D_MULTISAMPLE, 0);

        glBindRenderbuffer(GL_RENDERBUFFER, Test->Color_Renderbuffer);
        glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_RGBA8, Width, Height);

        glBindRenderbuffer(GL_RENDERBUFFER, (GLuint)Test->Stencil_Renderbuffer );
        glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_STENCIL_INDEX8, Width, Height );
    } else {
        glTexParameteri(Target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        glTexParameteri(Target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        glTexParameteri(Target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
        glTexParameteri(Target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
        // glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, Width, Height, 0, GL_RGBA,
        //              GL_UNSIGNED_BYTE, Data);
        glBindTexture(GL_TEXTURE_2D, 0);

        glBindRenderbuffer(GL_RENDERBUFFER, Test->Color_Renderbuffer);
        glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, Width, Height);

        glBindRenderbuffer(GL_RENDERBUFFER, (GLuint)Test->Stencil_Renderbuffer );
        glRenderbufferStorage(GL_RENDERBUFFER, GL_STENCIL_INDEX8, Width, Height );
    }

    glBindFramebuffer(GL_FRAMEBUFFER, Test->FramebufferObject);

    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, Test->Color_Renderbuffer);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, Test->Stencil_Renderbuffer);

    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (status != GL_FRAMEBUFFER_COMPLETE) {
        printf("incomplete framebuffer");
        Assert(0);
    }

    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

static void
GL_BindDefaultVertexArrays()
{
    glBindVertexArray(DefaultVerts.VertexArrayObject);
    // Switch to main buffer
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, DefaultVerts.ElementBufferObject);
    glBindBuffer(GL_ARRAY_BUFFER, DefaultVerts.VertexBufferObject);
    glBufferData(GL_ARRAY_BUFFER, sizeof(GL_DefaultVertices), GL_DefaultVertices, GL_STATIC_DRAW);
    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);
    // texture coordinate (note the last parameter's offset)
    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5 * sizeof(float), (void*)(3 * sizeof(float)));
    glEnableVertexAttribArray(1);

}

static void
GL_RasterizeShape(project_layer *Layer, mask *Mask)
{
    gl_effect_layer Test = Layer->BitmapInfo.TestM;
    gl_effect_layer Test2 = Layer->BitmapInfo.Test;
    gl_vertex_shader VertData;

    uint32 Width = Layer->Source->Info.Width;
    uint32 Height = Layer->Source->Info.Height;

    uint8 *Data = (uint8 *)Layer->BitmapInfo.BitmapBuffer;
    glBindFramebuffer(GL_FRAMEBUFFER, Test.FramebufferObject);

	glEnable(GL_STENCIL_TEST);
    // glStencilOp(GL_KEEP, GL_REPLACE, GL_REPLACE);
	glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
    glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);

    glStencilFunc(GL_ALWAYS, 0, 0xFF);   // always write
    glStencilMask(0xff);                 // allow writing; ANDs any writes to the stencil buffer with this

	glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE);

    glUseProgram(DefaultShaderProgram);

    int VertexMode = glGetUniformLocation(DefaultShaderProgram, "VertexMode");
    int FragmentMode = glGetUniformLocation(DefaultShaderProgram, "FragmentMode");
    glUniform1i(VertexMode, 1);
    glUniform1i(FragmentMode, 0);

    // secondary VBO
    glGenVertexArrays(1, &VertData.VertexArrayObject);
    glGenBuffers(1, &VertData.VertexBufferObject);
    glBindVertexArray(VertData.VertexArrayObject);
    glBindBuffer(GL_ARRAY_BUFFER, VertData.VertexBufferObject);
    glBufferData(GL_ARRAY_BUFFER, Mask->NumberOfVerts*3*sizeof(real32), Mask->TriangulatedPointCache, GL_STREAM_DRAW);

    // position attribute
    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0);
    glEnableVertexAttribArray(0);

    int Scale = glGetUniformLocation(DefaultShaderProgram, "CompDimensions");
    glUniform3f(Scale, Width, Height, 0);


	glStencilOpSeparate(GL_FRONT, GL_KEEP, GL_KEEP, GL_INCR_WRAP);
	glStencilOpSeparate(GL_BACK, GL_KEEP, GL_KEEP, GL_DECR_WRAP);

	glDisable(GL_CULL_FACE);

	glDrawArrays(GL_TRIANGLE_FAN, 0, Mask->NumberOfVerts);

	// glEnable(GL_CULL_FACE);

	glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE);

    glBindVertexArray(0);

    // glBindRenderbuffer(GL_RENDERBUFFER, Test.Color_Renderbuffer);

    VertexMode = glGetUniformLocation(DefaultShaderProgram, "VertexMode");
    FragmentMode = glGetUniformLocation(DefaultShaderProgram, "FragmentMode");
    glUniform1i(VertexMode, 0);
    glUniform1i(FragmentMode, 1);

    GL_BindDefaultVertexArrays();

    glStencilFunc(GL_NOTEQUAL, 0, 0xFF);
	glStencilOp(GL_ZERO, GL_ZERO, GL_ZERO);
    glDrawElements(GL_TRIANGLE_STRIP, 6, GL_UNSIGNED_INT, 0);

	glDisable(GL_STENCIL_TEST);
    glStencilMask(0xFF);
    glStencilFunc(GL_ALWAYS, 0, 0xFF);

    glBindFramebuffer(GL_READ_FRAMEBUFFER, Test.FramebufferObject);
    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, Test2.FramebufferObject);
    glBlitFramebuffer(0, 0, Width, Height, 0, 0, Width, Height,
                      GL_COLOR_BUFFER_BIT, GL_NEAREST);
    glBindFramebuffer(GL_FRAMEBUFFER, Test2.FramebufferObject);

    glReadPixels(0, 0, Width, Height, GL_RGBA, GL_UNSIGNED_BYTE, &Data[0]);

    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

static uint16
Effect_GL_InitShader(int EffectIndex)
{
    uint16 *ShaderProgram = &GL_EffectShaderProgram[EffectIndex];

    // this is safe to do, riiight
    if (*ShaderProgram) {
        glUseProgram(*ShaderProgram);
        return *ShaderProgram;
    }

    glShaderSource(DefaultVertexShader, 1, &DefaultVertexShaderSource, NULL);
    glCompileShader(DefaultVertexShader);

    int success;
    char infoLog[512];
    glGetShaderiv(DefaultVertexShader, GL_COMPILE_STATUS, &success);

    if(!success)
    {
        glGetShaderInfoLog(DefaultVertexShader, 512, NULL, infoLog);
        printf("Vertex shader fail:\n %s", infoLog);
    }

    uint32 FragmentShader = glCreateShader(GL_FRAGMENT_SHADER);

    glShaderSource(FragmentShader, 1, &FragmentShaderEffectSource[EffectIndex], NULL);
    glCompileShader(FragmentShader);

    glGetShaderiv(FragmentShader, GL_COMPILE_STATUS, &success);

    if(!success)
    {
        glGetShaderInfoLog(FragmentShader, 512, NULL, infoLog);
        printf("Fragment shader fail:\n %s", infoLog);
    }

    *ShaderProgram = glCreateProgram();

    glAttachShader(*ShaderProgram, DefaultVertexShader);
    glAttachShader(*ShaderProgram, FragmentShader);
    glLinkProgram(*ShaderProgram);

    glGetProgramiv(*ShaderProgram, GL_LINK_STATUS, &success);
    if(!success) {
        glGetProgramInfoLog(*ShaderProgram, 512, NULL, infoLog);
        printf("Shader linkage fail:\n %s", infoLog);
    }

    glDeleteShader(FragmentShader);

    glUseProgram(*ShaderProgram);

    return *ShaderProgram;
}
#endif