First commit

src/canvas.cpp

@@ -0,0 +1,146 @@
+#include "canvas.h"
+#include <glm/gtc/type_ptr.hpp>
+
+using namespace glm;
+using namespace game::resource;
+
+namespace game
+{
+  GLuint Canvas::textureVAO = 0;
+  GLuint Canvas::textureVBO = 0;
+  GLuint Canvas::textureEBO = 0;
+  bool Canvas::isStaticInit = false;
+
+  Canvas::Canvas(vec2 size, bool isDefault)
+  {
+    this->size = size;
+
+    if (isDefault)
+    {
+      fbo = 0;
+      rbo = 0;
+      texture = 0;
+      this->isDefault = true;
+    }
+    else
+    {
+      glGenFramebuffers(1, &fbo);
+      glGenRenderbuffers(1, &rbo);
+      glGenTextures(1, &texture);
+
+      glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+
+      glBindTexture(GL_TEXTURE_2D, texture);
+      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, size.x, size.y, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+      glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
+
+      glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+      glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, size.x, size.y);
+      glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, rbo);
+      glBindRenderbuffer(GL_RENDERBUFFER, 0);
+
+      glBindFramebuffer(GL_FRAMEBUFFER, 0);
+    }
+
+    if (!isStaticInit)
+    {
+      glGenVertexArrays(1, &textureVAO);
+      glGenBuffers(1, &textureVBO);
+      glGenBuffers(1, &textureEBO);
+
+      glBindVertexArray(textureVAO);
+
+      glBindBuffer(GL_ARRAY_BUFFER, textureVBO);
+      glBufferData(GL_ARRAY_BUFFER, sizeof(float) * 4 * 4, nullptr, GL_DYNAMIC_DRAW);
+
+      glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, textureEBO);
+      glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(TEXTURE_INDICES), TEXTURE_INDICES, GL_DYNAMIC_DRAW);
+
+      glEnableVertexAttribArray(0);
+      glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)0);
+
+      glEnableVertexAttribArray(1);
+      glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 4 * sizeof(float), (void*)(2 * sizeof(float)));
+
+      glBindVertexArray(0);
+    }
+  }
+
+  Canvas::~Canvas()
+  {
+    if (!isDefault)
+    {
+      if (fbo) glDeleteFramebuffers(1, &fbo);
+      if (rbo) glDeleteRenderbuffers(1, &rbo);
+      if (texture) glDeleteTextures(1, &texture);
+    }
+  }
+
+  mat4 Canvas::view_get() const { return mat4{1.0f}; }
+  mat4 Canvas::projection_get() const
+  {
+    if (isDefault) return glm::ortho(0.0f, (float)size.x, (float)size.y, 0.0f, -1.0f, 1.0f);
+    return glm::ortho(0.0f, (float)size.x, 0.0f, (float)size.y, -1.0f, 1.0f);
+  }
+
+  void Canvas::texture_render(Shader& shader, GLuint textureId, mat4& model, vec4 tint, vec3 colorOffset,
+                              float* vertices) const
+  {
+    auto view = view_get();
+    auto projection = projection_get();
+
+    glUseProgram(shader.id);
+
+    glUniform1i(glGetUniformLocation(shader.id, shader::UNIFORM_TEXTURE), 0);
+    glUniform3fv(glGetUniformLocation(shader.id, shader::UNIFORM_COLOR_OFFSET), 1, value_ptr(colorOffset));
+    glUniform4fv(glGetUniformLocation(shader.id, shader::UNIFORM_TINT), 1, value_ptr(tint));
+
+    glUniformMatrix4fv(glGetUniformLocation(shader.id, shader::UNIFORM_MODEL), 1, GL_FALSE, value_ptr(model));
+    glUniformMatrix4fv(glGetUniformLocation(shader.id, shader::UNIFORM_VIEW), 1, GL_FALSE, value_ptr(view));
+    glUniformMatrix4fv(glGetUniformLocation(shader.id, shader::UNIFORM_PROJECTION), 1, GL_FALSE, value_ptr(projection));
+
+    glBindVertexArray(textureVAO);
+
+    glBindBuffer(GL_ARRAY_BUFFER, textureVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(TEXTURE_VERTICES), vertices, GL_DYNAMIC_DRAW);
+
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, textureId);
+
+    glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+
+    glBindVertexArray(0);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindTexture(GL_TEXTURE_2D, 0);
+    glUseProgram(0);
+  }
+
+  void Canvas::render(Shader& shader, mat4& model, vec4 tint, vec3 colorOffset) const
+  {
+    texture_render(shader, texture, model, tint, colorOffset);
+  }
+
+  void Canvas::bind() const
+  {
+    glBindFramebuffer(GL_FRAMEBUFFER, fbo);
+    glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+    glViewport(0, 0, size.x, size.y);
+  }
+
+  void Canvas::clear(vec4 color) const
+  {
+    glClearColor(color.r, color.g, color.b, color.a);
+    glClear(GL_COLOR_BUFFER_BIT);
+  }
+
+  void Canvas::unbind() const
+  {
+    glBindRenderbuffer(GL_RENDERBUFFER, 0);
+    glBindFramebuffer(GL_FRAMEBUFFER, 0);
+  }
+
+  bool Canvas::is_valid() const { return fbo != 0 || isDefault; };
+}