initial commit

.gitignore

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+zig-cache
+zig-out

README.md

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+# OpenGL "Hello, Triangle" example
+
+To run this example you need to have glfw, opengl and glew installed on your system.
+```
+zig build run
+```
+
+Followed this tutorial: https://antongerdelan.net/opengl/hellotriangle.html

build.zig

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+const std = @import("std");
+
+pub fn build(b: *std.build.Builder) void {
+    const target = b.standardTargetOptions(.{});
+    const optimize = b.standardOptimizeOption(.{});
+
+    const exe = b.addExecutable(.{
+        .name = "opengl-example",
+        .root_source_file = .{ .path = "main.c" },
+        .optimize = optimize,
+        .target = target
+    });
+    exe.linkLibC();
+    exe.linkSystemLibrary("GL");
+    exe.linkSystemLibrary("glfw");
+    exe.linkSystemLibrary("GLEW");
+
+    const run_cmd = b.addRunArtifact(exe);
+    const run_step = b.step("run", "Run simple program");
+    run_step.dependOn(&run_cmd.step);
+
+    b.installArtifact(exe);
+}

main.c

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+#include <stdio.h>
+#include <GL/glew.h>
+#define GLFW_DLL
+#include <GLFW/glfw3.h>
+
+#define eprint(fmt, ...) fprintf(stderr, "ERROR: " fmt  "\n" #__VA_ARGS__)
+
+const char *vertex_shader =
+	"#version 330 core\n"
+	"in vec3 vp;\n"
+	"void main() {\n"
+	"  gl_Position = vec4(vp, 1.0);\n"
+	"}\n";
+
+const char *fragment_shader =
+	"#version 330 core\n"
+	"out vec4 fragColor;\n"
+	"void main() {\n"
+	"  fragColor = vec4(0.5, 0.0, 0.5, 1.0);\n"
+	"}\n";
+
+int main() {
+	if (!glfwInit()) {
+		eprint("Could not start glfw");
+		return -1;
+	}
+
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
+	glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 2);
+	glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
+	glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE);
+
+	GLFWwindow *window = glfwCreateWindow(640, 480, "Hello triangle", NULL, NULL);
+	if (!window) {
+		eprint("Could not open window with glfw");
+		glfwTerminate();
+		return -1;
+	}
+	glfwMakeContextCurrent(window);
+
+	glewExperimental = GL_TRUE;
+	glewInit();
+
+	printf("Renderer: %s\n", glGetString(GL_RENDERER));
+	printf("OpenGL version supported: %s\n", glGetString(GL_VERSION));
+
+	glEnable(GL_DEPTH_TEST);
+	glDepthFunc(GL_LESS);
+
+	float points[] = {
+		 0.0f,  0.5f, 0.0f,
+		 0.5f, -0.5f, 0.0f,
+		-0.5f, -0.5f, 0.0f,
+	};
+
+	GLuint vbo = 0;
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, 9 * sizeof(float), points, GL_STATIC_DRAW);
+
+	GLuint vao = 0;
+	glGenVertexArrays(1, &vao);
+	glBindVertexArray(vao);
+	glEnableVertexAttribArray(0);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 0, NULL);
+
+	GLuint vs = glCreateShader(GL_VERTEX_SHADER);
+	glShaderSource(vs, 1, &vertex_shader, NULL);
+	glCompileShader(vs);
+
+	GLuint fs = glCreateShader(GL_FRAGMENT_SHADER);
+	glShaderSource(fs, 1, &fragment_shader, NULL);
+	glCompileShader(fs);
+
+	GLuint shader_program = glCreateProgram();
+	glAttachShader(shader_program, fs);
+	glAttachShader(shader_program, vs);
+	glLinkProgram(shader_program);
+
+	while (!glfwWindowShouldClose(window)) {
+		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+		glUseProgram(shader_program);
+		glBindVertexArray(vao);
+		glDrawArrays(GL_TRIANGLES, 0, 3);
+		glfwPollEvents();
+		glfwSwapBuffers(window);
+	}
+
+
+	glfwTerminate();
+	return 0;
+}