Lower required OpenGL version from 4.6 to 4.0

sunverwerth · Sep 27, 2020 · 2d6baad · 2d6baad
1 parent cd3a263
commit 2d6baad
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Showing 3 changed files with 34 additions and 29 deletions.
diff --git a/src/Gfx.cpp b/src/Gfx.cpp
@@ -46,7 +46,7 @@ Gfx::Gfx(const char* title, int width, int height, bool fullscreen) {
 	SDL_GetWindowSize(window, &width_, &height_);
 
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
-	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 6);
+	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 0);
 	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 	SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, SDL_TRUE);
 	unsigned int flags = SDL_GL_CONTEXT_FORWARD_COMPATIBLE_FLAG;
@@ -66,6 +66,7 @@ Gfx::Gfx(const char* title, int width, int height, bool fullscreen) {
 #ifdef _DEBUG
 	if (glDebugMessageCallback) {
 		glEnable(GL_DEBUG_OUTPUT);
+		glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
 		glDebugMessageCallback(debugCallback, nullptr);
 	}
 #endif

diff --git a/src/Mesh.cpp b/src/Mesh.cpp
@@ -30,10 +30,24 @@ SOFTWARE.
 Mesh::Mesh() {
 	int numQuads = 65536 / 4;
 
-	glCreateBuffers(1, &vbo);
-	glNamedBufferStorage(vbo, sizeof(SpriteVertex) * numQuads * 4, nullptr, GL_DYNAMIC_STORAGE_BIT);
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(SpriteVertex) * numQuads * 4, nullptr, GL_DYNAMIC_DRAW);
+
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(SpriteVertex), (void*)offsetof(SpriteVertex, position));
+
+	glEnableVertexAttribArray(1);
+	glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, sizeof(SpriteVertex), (void*)offsetof(SpriteVertex, uv));
+
+	glEnableVertexAttribArray(2);
+	glVertexAttribPointer(2, 4, GL_FLOAT, GL_FALSE, sizeof(SpriteVertex), (void*)offsetof(SpriteVertex, color));
 
-	glCreateBuffers(1, &ebo);
+	glGenBuffers(1, &ebo);
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
 	int numIndices = numQuads * 6;
 	std::vector<unsigned short> indices(numIndices);
 	for (int i = 0; i < numQuads; i++) {
@@ -44,23 +58,7 @@ Mesh::Mesh() {
 		indices[i * 6 + 4] = i * 4 + 3;
 		indices[i * 6 + 5] = i * 4 + 0;
 	}
-	glNamedBufferStorage(ebo, sizeof(unsigned short) * numIndices, indices.data(), 0);
-
-	glCreateVertexArrays(1, &vao);
-	glVertexArrayVertexBuffer(vao, 0, vbo, 0, sizeof(SpriteVertex));
-	glVertexArrayElementBuffer(vao, ebo);
-
-	glEnableVertexArrayAttrib(vao, 0);
-	glVertexArrayAttribBinding(vao, 0, 0);
-	glVertexArrayAttribFormat(vao, 0, 2, GL_FLOAT, GL_FALSE, offsetof(SpriteVertex, position));
-
-	glEnableVertexArrayAttrib(vao, 1);
-	glVertexArrayAttribBinding(vao, 1, 0);
-	glVertexArrayAttribFormat(vao, 1, 2, GL_FLOAT, GL_FALSE, offsetof(SpriteVertex, uv));
-
-	glEnableVertexArrayAttrib(vao, 2);
-	glVertexArrayAttribBinding(vao, 2, 0);
-	glVertexArrayAttribFormat(vao, 2, 4, GL_FLOAT, GL_FALSE, offsetof(SpriteVertex, color));
+	glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(unsigned short) * numIndices, indices.data(), GL_DYNAMIC_DRAW);
 }
 
 Mesh::~Mesh() {
@@ -70,10 +68,12 @@ Mesh::~Mesh() {
 }
 
 void Mesh::bind() const {
+	glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo);
 	glBindVertexArray(vao);
 }
 
 void Mesh::setVertices(const void* data, size_t elementSize, int num) {
-	glNamedBufferSubData(vbo, 0, elementSize * num, data);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferSubData(GL_ARRAY_BUFFER, 0, elementSize * num, data);
 	numVertices_ = num;
 }
diff --git a/src/Texture.cpp b/src/Texture.cpp
@@ -28,10 +28,11 @@ SOFTWARE.
 #include "sys.h"
 
 Texture::Texture(const Image& image): width_(image.width()), height_(image.height()) {
-	glCreateTextures(GL_TEXTURE_2D, 1, &texture);
-	glTextureStorage2D(texture, 1, GL_RGBA8, width_, height_);
-	glTextureParameteri(texture, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
-	glTextureParameteri(texture, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+	glGenTextures(1, &texture);
+	glBindTexture(GL_TEXTURE_2D, texture);
+	glTexImage2D(GL_TEXTURE_2D, 0, image.format() == Image::Format::RGB8 ? GL_RGB8 : GL_RGBA8, width_, height_, 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);
 	load(image);
 }
 
@@ -45,17 +46,20 @@ void Texture::load(const Image& image) {
 		return;
 	}
 
-	glTextureSubImage2D(texture, 0, 0, 0, width_, height_, image.format() == Image::Format::RGB8 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, image.data());
+	glBindTexture(GL_TEXTURE_2D, texture);
+	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, width_, height_, image.format() == Image::Format::RGB8 ? GL_RGB : GL_RGBA, GL_UNSIGNED_BYTE, image.data());
 }
 
 void Texture::bind(int unit) {
 	if (unit_ >= 0) unbind();
 	unit_ = unit;
-	glBindTextureUnit(unit_, texture);
+	glActiveTexture(GL_TEXTURE0 + unit_);
+	glBindTexture(GL_TEXTURE_2D, texture);
 }
 
 void Texture::unbind() {
 	if (unit_ < 0) return;
-	glBindTextureUnit(unit_, 0);
+	glActiveTexture(GL_TEXTURE0 + unit_);
+	glBindTexture(GL_TEXTURE_2D, 0);
 	unit_ = -1;
 }