The Update(TM), Part 1

src/canvas.cpp

@@ -0,0 +1,50 @@
+// Common rendering area
+
+#include "canvas.h"
+
+void canvas_init(Canvas* self, vec2 size)
+{
+    self->size = size;
+
+    glGenFramebuffers(1, &self->fbo);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, self->fbo);
+
+    glGenTextures(1, &self->texture);
+    glBindTexture(GL_TEXTURE_2D, self->texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, (s32)self->size.x, (s32)self->size.y, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+
+    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, self->texture, 0);
+
+    glGenRenderbuffers(1, &self->rbo);
+    glBindRenderbuffer(GL_RENDERBUFFER, self->rbo);
+    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, (s32)self->size.x, (s32)self->size.y);
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, self->rbo);
+
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+
+    // Texture
+    glGenVertexArrays(1, &self->textureVAO);
+    glGenBuffers(1, &self->textureVBO);
+    glGenBuffers(1, &self->textureEBO);
+
+    glBindVertexArray(self->textureVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, self->textureVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(f32) * 4 * 4, nullptr, GL_DYNAMIC_DRAW);
+
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, self->textureEBO);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(GL_TEXTURE_INDICES), GL_TEXTURE_INDICES, GL_STATIC_DRAW);
+
+    // Position attribute
+    glEnableVertexAttribArray(0); 
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(f32), (void*)0);
+
+    // UV attribute
+    glEnableVertexAttribArray(1); 
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(f32), (void*)(2 * sizeof(f32)));
+
+    glBindVertexArray(0);
+}