gaming-core/rendering/GL.cpp

#include "rendering/GL.h"

#include <type_traits>

#include "GL/glew.h"
#include "data/Array.h"
#include "utils/Logger.h"

static_assert(std::is_same<GL::Shader, GLuint>::value,
              "shader has invalid type");
static_assert(std::is_same<GL::Program, GLuint>::value, "p has invalid type");
static_assert(std::is_same<char, GLchar>::value, "char has invalid type");
static_assert(std::is_same<int, GLint>::value, "int has invalid type");
static_assert(std::is_same<float, GLfloat>::value, "float has invalid type");
static_assert(std::is_same<GL::Texture, GLuint>::value,
              "texture has invalid type");
static_assert(std::is_same<GL::Framebuffer, GLuint>::value,
              "framebuffer has invalid type");
static_assert(std::is_same<GL::ColorAttachment, GLenum>::value,
              "color attachment has invalid type");
static_assert(std::is_same<GL::VertexArray, GLuint>::value,
              "vertex array has invalid type");
static_assert(std::is_same<GL::Buffer, GLuint>::value,
              "buffer has invalid type");

GL::Attribute::Attribute(int count_, int size_, int type_, bool normalized_)
    : count(count_), size(size_), type(type_), normalized(normalized_) {
}

GL::Attribute GL::Attribute::newFloat(int count) {
    return GL::Attribute(count, sizeof(float), GL_FLOAT, false);
}

GL::Attribute GL::Attribute::newColor(int count) {
    return GL::Attribute(count, sizeof(unsigned char), GL_UNSIGNED_BYTE, true);
}

GL::Attribute GL::Attribute::newDummy() {
    return GL::Attribute(0, 0, -1, false);
}

bool GL::Attribute::isDummy() const {
    return type == -1;
}

int GL::Attribute::getSize() const {
    return count * size;
}

GL::TextureFormat::TextureFormat(int internalformat_, int format_, int type_)
    : internalformat(internalformat_), format(format_), type(type_) {
}

GL::TextureFormat GL::TextureFormat::color8(int channels) {
    switch(channels) {
        case 1: return TextureFormat(GL_RED, GL_RED, GL_UNSIGNED_BYTE);
        case 2: return TextureFormat(GL_RG, GL_RG, GL_UNSIGNED_BYTE);
        case 3: return TextureFormat(GL_RGB, GL_RGB, GL_UNSIGNED_BYTE);
        case 4: return TextureFormat(GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE);
    }
    LOG_ERROR(StringBuffer<50>(channels).append(
        " is not a valid amount of channels"));
    return unknown();
}

GL::TextureFormat GL::TextureFormat::float16(int channels) {
    switch(channels) {
        case 1: return TextureFormat(GL_R16F, GL_RED, GL_FLOAT);
        case 2: return TextureFormat(GL_RG16F, GL_RG, GL_FLOAT);
        case 3: return TextureFormat(GL_RGB16F, GL_RGB, GL_FLOAT);
        case 4: return TextureFormat(GL_RGBA16F, GL_RGBA, GL_FLOAT);
    }
    LOG_ERROR(StringBuffer<50>(channels).append(
        " is not a valid amount of channels"));
    return unknown();
}

GL::TextureFormat GL::TextureFormat::float32(int channels) {
    switch(channels) {
        case 1: return TextureFormat(GL_R32F, GL_RED, GL_FLOAT);
        case 2: return TextureFormat(GL_RG32F, GL_RG, GL_FLOAT);
        case 3: return TextureFormat(GL_RGB32F, GL_RGB, GL_FLOAT);
        case 4: return TextureFormat(GL_RGBA32F, GL_RGBA, GL_FLOAT);
    }
    LOG_ERROR(StringBuffer<50>(channels).append(
        " is not a valid amount of channels"));
    return unknown();
}

GL::TextureFormat GL::TextureFormat::depth16() {
    return TextureFormat(GL_DEPTH_COMPONENT16, GL_DEPTH_COMPONENT, GL_FLOAT);
}

GL::TextureFormat GL::TextureFormat::depth32() {
    return TextureFormat(GL_DEPTH_COMPONENT32, GL_DEPTH_COMPONENT, GL_FLOAT);
}

GL::TextureFormat GL::TextureFormat::unknown() {
    return TextureFormat(-1, -1, -1);
}

bool GL::printError(const char* message) {
    GLenum error = glGetError();
    if(error != GL_NO_ERROR) {
        (void)message;
        LOG_ERROR(StringBuffer<100>(message).append(": ").append(error));
        return true;
    }
    return false;
}

Error GL::getError(const char* message) {
    GLenum error = glGetError();
    if(error != GL_NO_ERROR) {
        Error e = {message};
        e.message.append(": ").append(error);
        return e;
    }
    return {};
}

void GL::enableDepthTesting() {
    glEnable(GL_DEPTH_TEST);
}

void GL::disableDepthTesting() {
    glDisable(GL_DEPTH_TEST);
}

void GL::bindMainFramebuffer() {
    glBindFramebuffer(GL_FRAMEBUFFER, 0);
}

void GL::clear() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}

void GL::enableBlending() {
    glEnable(GL_BLEND);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glBlendEquation(GL_FUNC_ADD);
}

void GL::disableBlending() {
    glDisable(GL_BLEND);
}

void GL::setViewport(int width, int height) {
    glViewport(0, 0, width, height);
}

void GL::vertexAttribPointer(int index, const Attribute& a, int stride,
                             int offset) {
    glVertexAttribPointer(static_cast<GLuint>(index), a.count,
                          static_cast<GLenum>(a.type), a.normalized, stride,
                          static_cast<char*>(0) + offset);
    glEnableVertexAttribArray(static_cast<GLuint>(index));
}

GL::Program GL::createProgram() {
    return glCreateProgram();
}

void GL::attachShader(Program p, Shader s) {
    glAttachShader(p, s);
}

void GL::linkProgram(Program p) {
    glLinkProgram(p);
}

Error GL::getLinkerError(Program p) {
    GLint linked;
    glGetProgramiv(p, GL_LINK_STATUS, &linked);
    if(!linked) {
        Array<char, 256> log;
        glGetProgramInfoLog(p, log.getLength(), nullptr, log.begin());
        Error e = {"linker log: "};
        e.message.append(static_cast<const char*>(log.begin()));
        return e;
    }
    return {};
}

void GL::deleteShader(Shader s) {
    if(s != 0) {
        glDeleteShader(s);
    }
}

void GL::deleteProgram(Program p) {
    if(p != 0) {
        glDeleteProgram(p);
    }
}

GL::Shader GL::createShader(ShaderType type) {
    static constexpr GLenum MAP[] = {0,
                                     GL_VERTEX_SHADER,
                                     GL_FRAGMENT_SHADER,
                                     GL_GEOMETRY_SHADER,
                                     GL_TESS_CONTROL_SHADER,
                                     GL_TESS_EVALUATION_SHADER};
    static constexpr int MAP_SIZE =
        static_cast<int>(sizeof(MAP) / sizeof(GLenum));
    int index = static_cast<int>(type);
    GLenum realTyp = index < 0 || index >= MAP_SIZE ? MAP[0] : MAP[index];
    return glCreateShader(realTyp);
}

void GL::compileShader(Shader s, const char* code) {
    glShaderSource(s, 1, &code, nullptr);
    glCompileShader(s);
}

Error GL::getCompileError(Shader s) {
    GLint compiled;
    glGetShaderiv(s, GL_COMPILE_STATUS, &compiled);
    if(!compiled) {
        Array<char, 256> log;
        glGetShaderInfoLog(s, log.getLength(), nullptr, log.begin());
        Error e = {"compiler log: "};
        e.message.append(static_cast<const char*>(log.begin()));
        return e;
    }
    return {};
}

void GL::useProgram(Program p) {
    glUseProgram(p);
}

void GL::setMatrix(Program p, const char* name, const float* data) {
    glUniformMatrix4fv(glGetUniformLocation(p, name), 1, GL_TRUE, data);
}

void GL::setInt(Program p, const char* name, int data) {
    glUniform1i(glGetUniformLocation(p, name), data);
}

void GL::setFloat(Program p, const char* name, float data) {
    glUniform1f(glGetUniformLocation(p, name), data);
}

void GL::set2Float(Program p, const char* name, const float* data) {
    glUniform2fv(glGetUniformLocation(p, name), 1, data);
}

void GL::set3Float(Program p, const char* name, const float* data) {
    glUniform3fv(glGetUniformLocation(p, name), 1, data);
}

void GL::set4Float(Program p, const char* name, const float* data) {
    glUniform4fv(glGetUniformLocation(p, name), 1, data);
}

void GL::texImage2D(const TextureFormat& tf, int width, int height,
                    const void* data, int level) {
    glTexImage2D(GL_TEXTURE_2D, level, tf.internalformat, width, height, 0,
                 static_cast<GLenum>(tf.format), static_cast<GLenum>(tf.type),
                 data);
}

GL::Texture GL::genTexture() {
    Texture t;
    glGenTextures(1, &t);
    return t;
}

void GL::deleteTexture(Texture t) {
    if(t != 0) {
        glDeleteTextures(1, &t);
    }
}

void GL::setNearFilter2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}

void GL::setMipMapNearFilter2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
                    GL_NEAREST_MIPMAP_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
}

void GL::setLinearFilter2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}

void GL::setMipMapLinearFilter2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
                    GL_LINEAR_MIPMAP_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
}

void GL::setClampWrap2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
}

void GL::setRepeatWrap2D() {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
}

void GL::bindTexture2D(Texture t) {
    glBindTexture(GL_TEXTURE_2D, t);
}

void GL::activeTexture(int index) {
    glActiveTexture(static_cast<GLenum>(GL_TEXTURE0 + index));
}

void GL::generateMipmap2D(int maxLevels) {
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 0);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, maxLevels);
    glGenerateMipmap(GL_TEXTURE_2D);
}

void GL::deleteFramebuffers(Framebuffer fb) {
    if(fb != 0) {
        glDeleteFramebuffers(1, &fb);
    }
}

GL::Framebuffer GL::genFramebuffer() {
    Framebuffer fb;
    glGenFramebuffers(1, &fb);
    return fb;
}

void GL::bindFramebuffer(Framebuffer fb) {
    glBindFramebuffer(GL_FRAMEBUFFER, fb);
}

void GL::framebufferDepthTexture2D(Texture t) {
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D,
                           t, 0);
}

GL::ColorAttachment GL::framebufferColorTexture2D(Texture t, int index) {
    GLenum c = static_cast<GLenum>(GL_COLOR_ATTACHMENT0 + index);
    glFramebufferTexture2D(GL_FRAMEBUFFER, c, GL_TEXTURE_2D, t, 0);
    return c;
}

void GL::drawBuffers(int length, ColorAttachment* c) {
    glDrawBuffers(length, c);
}

Error GL::getFramebufferError() {
    GLenum error = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if(error != GL_FRAMEBUFFER_COMPLETE) {
        Error e = {"framebuffer error: "};
        e.message.append(error);
        return e;
    }
    return {};
}

GL::VertexArray GL::genVertexArray() {
    VertexArray va;
    glGenVertexArrays(1, &va);
    return va;
}

GL::Buffer GL::genBuffer() {
    Buffer b;
    glGenBuffers(1, &b);
    return b;
}

void GL::deleteBuffer(Buffer b) {
    if(b != 0) {
        glDeleteBuffers(1, &b);
    }
}

void GL::deleteVertexArray(VertexArray va) {
    if(va != 0) {
        glDeleteVertexArrays(1, &va);
    }
}

void GL::bindVertexArray(VertexArray va) {
    glBindVertexArray(va);
}

void GL::bindBuffer(Buffer b) {
    glBindBuffer(GL_ARRAY_BUFFER, b);
}

void GL::bufferData(int size, const void* data, BufferUsage usage) {
    static constexpr GLenum MAP[] = {0, GL_STATIC_DRAW, GL_STREAM_DRAW,
                                     GL_DYNAMIC_DRAW};
    static constexpr int MAP_SIZE =
        static_cast<int>(sizeof(MAP) / sizeof(GLenum));
    int index = static_cast<int>(usage);
    GLenum realUsage = index < 0 || index >= MAP_SIZE ? MAP[0] : MAP[index];
    glBufferData(GL_ARRAY_BUFFER, size, data, realUsage);
}

void GL::bufferSubData(int offset, int size, const void* data) {
    glBufferSubData(GL_ARRAY_BUFFER, offset, size, data);
}

void GL::drawTriangles(int offset, int vertices) {
    glDrawArrays(GL_TRIANGLES, offset, vertices);
}

void GL::drawTriangleStrip(int offset, int vertices) {
    glDrawArrays(GL_TRIANGLE_STRIP, offset, vertices);
}

void GL::drawPoints(int offset, int vertices) {
    glDrawArrays(GL_POINTS, offset, vertices);
}