LearnOpenGL chapter 1

opengl/learn_opengl/1_getting_started/1_hello_window/main.odin

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+package main
+
+import gl "vendor:OpenGL"
+import "vendor:glfw"
+import "core:fmt"
+import "core:os"
+
+framebuffer_size_callback :: proc "c" (window: glfw.WindowHandle, width: i32, height: i32) {
+	gl.Viewport(0, 0, width, height)
+}
+
+processInput :: proc "c" (window: glfw.WindowHandle) {
+	if glfw.GetKey(window, glfw.KEY_ESCAPE) == glfw.PRESS {
+		glfw.SetWindowShouldClose(window, true)
+	}
+}
+
+main :: proc() {
+	glfw.Init()
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MAJOR, 3)
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MINOR, 3)
+	glfw.WindowHint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
+
+	window := glfw.CreateWindow(800, 600, "LearnOpenGL", nil, nil)
+	if window == nil {
+		fmt.println("Failed to create GLFW window")
+		glfw.Terminate()
+		os.exit(-1)
+	}
+	glfw.MakeContextCurrent(window)
+
+	gl.load_up_to(3, 3, glfw.gl_set_proc_address)
+
+	gl.Viewport(0, 0, 800, 600)
+
+	glfw.SetFramebufferSizeCallback(window, framebuffer_size_callback)
+
+	for !glfw.WindowShouldClose(window) {
+		processInput(window)
+
+		gl.ClearColor(0.2, 0.3, 0.3, 1.0)
+		gl.Clear(gl.COLOR_BUFFER_BIT)
+
+		glfw.SwapBuffers(window)
+		glfw.PollEvents()
+	}
+
+	glfw.Terminate()
+}

opengl/learn_opengl/1_getting_started/2_hello_triangle/main.odin

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+package main
+
+import gl "vendor:OpenGL"
+import "vendor:glfw"
+import "core:fmt"
+import "core:os"
+import "core:c"
+
+framebuffer_size_callback :: proc "c" (window: glfw.WindowHandle, width: i32, height: i32) {
+	gl.Viewport(0, 0, width, height)
+}
+
+processInput :: proc "c" (window: glfw.WindowHandle) {
+	if glfw.GetKey(window, glfw.KEY_ESCAPE) == glfw.PRESS {
+		glfw.SetWindowShouldClose(window, true)
+	}
+}
+
+vertexShaderSource: cstring = 
+`#version 330 core
+layout (location = 0) in vec3 aPos;
+void main()
+{
+	gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
+}`
+
+fragmentShaderSource: cstring = 
+`#version 330 core
+out vec4 FragColor;
+
+void main()
+{
+	FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);
+}`
+
+SCR_WIDTH :: 800
+SCR_HEIGHT :: 600
+
+main :: proc() {
+	glfw.Init()
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MAJOR, 3)
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MINOR, 3)
+	glfw.WindowHint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
+
+	window := glfw.CreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nil, nil)
+	if window == nil {
+		fmt.println("Failed to create GLFW window")
+		glfw.Terminate()
+		os.exit(-1)
+	}
+	glfw.MakeContextCurrent(window)
+
+	gl.load_up_to(3, 3, glfw.gl_set_proc_address)
+
+	gl.Viewport(0, 0, SCR_WIDTH, SCR_HEIGHT)
+
+	glfw.SetFramebufferSizeCallback(window, framebuffer_size_callback)
+
+	success: i32
+	infoLog: [512]c.char
+
+	vertexShader := gl.CreateShader(gl.VERTEX_SHADER)
+	gl.ShaderSource(vertexShader, 1, &vertexShaderSource, nil)
+	gl.CompileShader(vertexShader)
+
+	gl.GetShaderiv(vertexShader, gl.COMPILE_STATUS, &success)
+	if success != 1 {
+		gl.GetShaderInfoLog(vertexShader, 512, nil, raw_data(&infoLog))
+	}
+
+	fragmentShader := gl.CreateShader(gl.FRAGMENT_SHADER)
+	gl.ShaderSource(fragmentShader, 1, &fragmentShaderSource, nil)
+	gl.CompileShader(fragmentShader)
+
+	gl.GetShaderiv(fragmentShader, gl.COMPILE_STATUS, &success)
+	if success != 1 {
+		gl.GetShaderInfoLog(fragmentShader, 512, nil, raw_data(&infoLog))
+		os.exit(-1)
+	}
+
+	shaderProgram := gl.CreateProgram()
+	gl.AttachShader(shaderProgram, vertexShader)
+	gl.AttachShader(shaderProgram, fragmentShader)
+	gl.LinkProgram(shaderProgram)
+
+	gl.GetProgramiv(fragmentShader, gl.LINK_STATUS, &success)
+	if success != 1 {
+		gl.GetProgramInfoLog(fragmentShader, 512, nil, raw_data(&infoLog))
+		os.exit(-1)
+	}
+
+	gl.DeleteShader(vertexShader)
+	gl.DeleteShader(fragmentShader)
+
+	vertices := [?]f32 {
+		 0.5,  0.5, 0.0, 
+         0.5, -0.5, 0.0,
+        -0.5, -0.5, 0.0,
+        -0.5,  0.5, 0.0,
+	}
+
+	indices := [?]u32 {
+		0, 1, 3,
+		1, 2, 3,
+	}
+
+	VBO, VAO, EBO: u32
+	gl.GenVertexArrays(1, &VAO)
+	gl.GenBuffers(1, &VBO)
+	gl.GenBuffers(1, &EBO)
+
+	gl.BindVertexArray(VAO)
+
+	gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
+	gl.BufferData(gl.ARRAY_BUFFER, size_of(vertices), raw_data(&vertices), gl.STATIC_DRAW)
+
+	gl.BindBuffer(gl.ELEMENT_ARRAY_BUFFER, EBO)
+	gl.BufferData(gl.ELEMENT_ARRAY_BUFFER, size_of(indices), raw_data(&indices), gl.STATIC_DRAW)
+
+	gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 3 * size_of(f32), 0)
+	gl.EnableVertexAttribArray(0)
+
+	gl.BindBuffer(gl.ARRAY_BUFFER, 0)
+	gl.BindVertexArray(0)
+
+	for !glfw.WindowShouldClose(window) {
+		processInput(window)
+
+		gl.ClearColor(0.2, 0.3, 0.3, 1.0)
+		gl.Clear(gl.COLOR_BUFFER_BIT)
+
+		gl.UseProgram(shaderProgram)
+		gl.BindVertexArray(VAO)
+		gl.DrawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, nil)
+
+		glfw.SwapBuffers(window)
+		glfw.PollEvents()
+	}
+
+	gl.DeleteVertexArrays(1, &VAO)
+	gl.DeleteBuffers(1, &VBO)
+	gl.DeleteBuffers(1, &EBO)
+	gl.DeleteProgram(shaderProgram)
+
+	glfw.Terminate()
+}

opengl/learn_opengl/1_getting_started/3_shaders/main.odin

@@ -0,0 +1,99 @@
+package main
+
+import gl "vendor:OpenGL"
+import "vendor:glfw"
+import "core:fmt"
+import "core:os"
+
+framebuffer_size_callback :: proc "c" (window: glfw.WindowHandle, width: i32, height: i32) {
+	gl.Viewport(0, 0, width, height)
+}
+
+processInput :: proc "c" (window: glfw.WindowHandle) {
+	if glfw.GetKey(window, glfw.KEY_ESCAPE) == glfw.PRESS {
+		glfw.SetWindowShouldClose(window, true)
+	}
+}
+
+shader_set_bool :: proc(id: u32, name: cstring, value: bool) {
+	gl.Uniform1i(gl.GetUniformLocation(id, name), i32(value))
+}
+
+shader_set_int :: proc(id: u32, name: cstring, value: i32) {
+	gl.Uniform1i(gl.GetUniformLocation(id, name), value)
+}
+
+shader_set_float :: proc(id: u32, name: cstring, value: f32) {
+	gl.Uniform1f(gl.GetUniformLocation(id, name), value)
+}
+
+SCR_WIDTH :: 800
+SCR_HEIGHT :: 600
+
+main :: proc() {
+	glfw.Init()
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MAJOR, 3)
+	glfw.WindowHint(glfw.CONTEXT_VERSION_MINOR, 3)
+	glfw.WindowHint(glfw.OPENGL_PROFILE, glfw.OPENGL_CORE_PROFILE)
+
+	window := glfw.CreateWindow(SCR_WIDTH, SCR_HEIGHT, "LearnOpenGL", nil, nil)
+	if window == nil {
+		fmt.println("Failed to create GLFW window")
+		glfw.Terminate()
+		os.exit(-1)
+	}
+	glfw.MakeContextCurrent(window)
+
+	gl.load_up_to(3, 3, glfw.gl_set_proc_address)
+
+	gl.Viewport(0, 0, SCR_WIDTH, SCR_HEIGHT)
+
+	glfw.SetFramebufferSizeCallback(window, framebuffer_size_callback)
+
+	vertices := [?]f32 {
+         0.5, -0.5, 0.0,  1.0, 0.0, 0.0,
+        -0.5, -0.5, 0.0,  0.0, 1.0, 0.0,
+         0.0,  0.5, 0.0,  0.0, 0.0, 1.0,
+	}
+
+	// The shader loading they create can be replaced with just this
+	shaderProgram, loaded_ok := gl.load_shaders_file("./res/vertex.vs", "./res/fragment.fs")
+	if !loaded_ok {
+		os.exit(-1)
+	}
+
+	VBO, VAO: u32
+	gl.GenVertexArrays(1, &VAO)
+	gl.GenBuffers(1, &VBO)
+
+	gl.BindVertexArray(VAO)
+
+	gl.BindBuffer(gl.ARRAY_BUFFER, VBO)
+	gl.BufferData(gl.ARRAY_BUFFER, size_of(vertices), raw_data(&vertices), gl.STATIC_DRAW)
+
+	gl.VertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 6 * size_of(f32), 0)
+	gl.EnableVertexAttribArray(0)
+
+	gl.VertexAttribPointer(1, 3, gl.FLOAT, gl.FALSE, 6 * size_of(f32), 3 * size_of(f32))
+	gl.EnableVertexAttribArray(1)
+
+	for !glfw.WindowShouldClose(window) {
+		processInput(window)
+
+		gl.ClearColor(0.2, 0.3, 0.3, 1.0)
+		gl.Clear(gl.COLOR_BUFFER_BIT)
+
+		gl.UseProgram(shaderProgram)
+		gl.BindVertexArray(VAO)
+		gl.DrawArrays(gl.TRIANGLES, 0, 3)
+
+		glfw.SwapBuffers(window)
+		glfw.PollEvents()
+	}
+
+	gl.DeleteVertexArrays(1, &VAO)
+	gl.DeleteBuffers(1, &VBO)
+	gl.DeleteProgram(shaderProgram)
+
+	glfw.Terminate()
+}

opengl/learn_opengl/1_getting_started/3_shaders/res/fragment.fs

@@ -0,0 +1,8 @@
+#version 330 core
+out vec4 FragColor;  
+in vec3 ourColor;
+
+void main()
+{
+    FragColor = vec4(ourColor, 1.0);
+}

opengl/learn_opengl/1_getting_started/3_shaders/res/vertex.vs

@@ -0,0 +1,11 @@
+#version 330 core
+layout (location = 0) in vec3 aPos;   // the position variable has attribute position 0
+layout (location = 1) in vec3 aColor; // the color variable has attribute position 1
+
+out vec3 ourColor; // output a color to the fragment shader
+
+void main()
+{
+    gl_Position = vec4(aPos, 1.0);
+    ourColor = aColor; // set ourColor to the input color we got from the vertex data
+}