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#include <basic/defs.hpp>
#include <iterator>
#include <renderer/RenderGroup.hpp>
#include <renderer/opengl/GlRenderer.hpp>
#include <basic/math.hpp>
#include <renderer/Renderer.hpp>
#include <renderer/opengl/GlVertexBuffer.hpp>
#include <SDL3/SDL.h>
#include <SDL3/SDL_video.h>
#include <GL/glew.h>
#include <GL/gl.h>
#include <assert.h>
#include <cstdio>
void GLAPIENTRY
MessageCallback(GLenum source,
GLenum type,
GLuint id,
GLenum severity,
GLsizei length,
const GLchar* message,
const void* userParam)
{
fprintf(stderr, "GL CALLBACK: %s, type = 0x%x, severity = 0x%x, message = %s\n",
type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : "",
type,
severity,
message
);
}
GlRenderer::~GlRenderer() {
SDL_GL_DestroyContext(m_Context);
}
GlRenderer::GlRenderer(SDL_Window *window)
: m_Window(window), m_Context(nullptr) {
}
bool GlRenderer::Init() {
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
SDL_GLContext sdl_gl_context = SDL_GL_CreateContext(m_Window);
if (!sdl_gl_context) {
return false;
}
GLenum err = glewInit();
if (GLEW_OK != err)
{
fprintf(stderr, "Error: %s\n", glewGetErrorString(err));
SDL_GL_DestroyContext(sdl_gl_context);
return false;
}
#if 0
glEnable(GL_DEBUG_OUTPUT);
glDebugMessageCallback(MessageCallback, 0);
#endif
GLuint vertex_array;
glGenVertexArrays(1, &vertex_array);
glBindVertexArray(vertex_array);
// init rectangle rendering
if (!m_RectangleShader.InitProgram()) {
return false;
}
m_RectangleVertexBuffer.Init();
m_RectangleIndexBuffer.Init();
// init text rendering
if (!m_TextShader.InitProgram()) {
return false;
}
m_TextVertexBuffer.Init();
m_TextIndexBuffer.Init();
m_Context = sdl_gl_context;
return true;
}
void GlRenderer::Draw(RenderGroup& render_group) {
render_group.Sort();
float camera_width = render_group.m_CameraWidth;
float camera_height = render_group.m_CameraHeight;
glViewport(0, 0, render_group.m_ScreenWidth, render_group.m_ScreenHeight);
glClearColor(render_group.m_ClearColor.x,
render_group.m_ClearColor.y,
render_group.m_ClearColor.z,
1.0f);
glClear(GL_COLOR_BUFFER_BIT);
// viewport space
float scale = render_group.GetScale();
int32_t viewport_width = static_cast<int32_t>(camera_width * scale);
int32_t viewport_height = static_cast<int32_t>(camera_height * scale);
int32_t viewport_x0 = (render_group.m_ScreenWidth - viewport_width) / 2;
int32_t viewport_y0 = (render_group.m_ScreenHeight - viewport_height) / 2;
glViewport(viewport_x0, viewport_y0, viewport_width, viewport_height);
// draw batches
float last_z = -1;
for (auto [z, entity_index] : render_group.m_RSortEntries) {
REntity& render_entity = render_group.m_REntities[entity_index];
switch (render_entity.type) {
case REntityType_Rectangle: {
// clip space (from camera space to [-1, 1] for pos and [0, 2] for dim)
V3F32 pos = render_entity.rect.pos;
V2F32 dim = render_entity.rect.dim;
pos.x = 2*(pos.x / camera_width) - 1;
pos.y = 2*(pos.y / camera_height) - 1;
dim.x = 2*(dim.x / camera_width);
dim.y = 2*(dim.y / camera_height);
if (render_entity.rect.pos.z > last_z) {
DrawBatch();
last_z = z;
}
m_RectangleVertexBuffer.PushRectangle(pos, dim, render_entity.rect.color);
m_RectangleIndexBuffer.PushRectangle();
}
case REntityType_Bitmap: {
REntity_Bitmap& bitmap = render_entity.bitmap;
// clip space (from camera space to [-1, 1] for pos and [0, 2] for dim)
V3F32 pos = render_entity.bitmap.pos;
pos.x = 2*(pos.x / camera_width) - 1;
pos.y = 2*(pos.y / camera_height) - 1;
#if 0
// create setup texture
unsigned int texture_id;
glGenTextures(1, &texture_id);
glBindTexture(GL_TEXTURE_2D, texture_id);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, bitmap.width, bitmap.height, 0, GL_RGB, GL_UNSIGNED_BYTE, bitmap.data);
glGenerateMipmap(GL_TEXTURE_2D);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
// apply texture
glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8 * sizeof(float), (void*)(6 * sizeof(float)));
glEnableVertexAttribArray(2);
// delete texture
glDeleteTextures(1, &texture_id);
// 1) set vertex buffer
// 2) set texture coordinates
pos.x = 2*(pos.x / camera_width) - 1;
pos.y = 2*(pos.y / camera_height) - 1;
dim.x = 2*(dim.x / camera_width);
dim.y = 2*(dim.y / camera_height);
if (render_entity.rect.pos.z > last_z) {
DrawBatch();
last_z = z;
}
#endif
} break;
InvalidDefaultCase;
}
}
DrawBatch();
}
void GlRenderer::Present() {
SDL_GL_SwapWindow(m_Window);
}
void GlRenderer::DrawBatch() {
int32_t rectangle_index_count = static_cast<int32_t>(m_RectangleIndexBuffer.GetCount());
int32_t text_index_count = static_cast<int32_t>(m_TextIndexBuffer.GetCount());
if (rectangle_index_count) {
m_RectangleVertexBuffer.TransferData();
m_RectangleIndexBuffer.TransferData();
m_RectangleShader.UseProgram();
glDrawElements(GL_TRIANGLES, rectangle_index_count, GL_UNSIGNED_INT, 0);
m_RectangleVertexBuffer.Reset();
m_RectangleIndexBuffer.Reset();
}
if (text_index_count) {
m_TextVertexBuffer.TransferData();
m_TextIndexBuffer.TransferData();
m_TextShader.UseProgram();
glDrawElements(GL_TRIANGLES, text_index_count, GL_UNSIGNED_INT, 0);
m_TextVertexBuffer.Reset();
m_TextIndexBuffer.Reset();
}
}
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