Nickiel/zig-opengl
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

not working rect

Browse source
This commit is contained in:
Nickiel12 2024-10-07 18:44:02 -07:00
parent ef1786df22
commit ab6f468ef7
1 changed files with 163 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

165
src/main.zig
View file

@ -9,6 +9,29 @@ const gl = @cImport ({
});
const vertexShaderSource: [*c]const u8 =
\\ #version 460 core
\\ layout (location = 0) in vec3 aPos;
\\ void main() {
\\ gl_Position = vec4(aPos.x, aPos.y, aPos.z, 1.0);
\\ }
;
const fragementShaderSource: [*c]const u8 =
\\ #version 330 core
\\ out vec4 FragColor;
\\ void main() {
\\ FragColor = vec4(1.0f, 0.5f, 0.2f, 1.0f);
\\ }
;
const ShaderInitError = error {
VertexCompilation,
FragementCompilation,
ShaderProgramLinking,
};
pub fn main() void {
// var arena = std.heap.ArenaAllocator.init(std.heap.page_allocator);
@ -20,8 +43,6 @@ pub fn main() void {
if (res != gl.GL_TRUE) {
std.debug.panic("Could not initialize glfw! Exit code: {d}", .{ res });
}
gl.glfwWindowHint(gl.GLFW_CONTEXT_VERSION_MAJOR, 4);
gl.glfwWindowHint(gl.GLFW_CONTEXT_VERSION_MINOR, 6);
gl.glfwWindowHint(gl.GLFW_OPENGL_PROFILE, gl.GLFW_OPENGL_CORE_PROFILE);
@ -29,7 +50,6 @@ pub fn main() void {
// the two null params are monitor for fullscreen, and share window resources (???)
const window: ?*gl.GLFWwindow = gl.glfwCreateWindow(800, 600, "LearnOpenGL", null, null);
if (window == null) {
gl.glfwTerminate();
std.debug.panic("Could not instantiate window!", .{});
@ -37,25 +57,81 @@ pub fn main() void {
}
gl.glfwMakeContextCurrent(window);
const version: c_int = gl.gladLoadGL(gl.glfwGetProcAddress);
if (version == 0) {
std.debug.panic("Could not initialize GLAD", .{});
return;
}
gl.glViewport(0, 0, 800, 600);
// callback function returned?
_ = gl.glfwSetFramebufferSizeCallback(window, &framebuffer_resize_callback);
const vertexShader: c_uint = gl.glCreateShader(gl.GL_VERTEX_SHADER);
const fragShader: c_uint = gl.glCreateShader(gl.GL_FRAGMENT_SHADER);
const shaderProgram: c_uint = gl.glCreateProgram();
init_shader_program(&vertexShader, &fragShader, &shaderProgram) catch |e| switch (e) {
ShaderInitError.VertexCompilation => std.debug.panic("Could not compile vertex shader!\n", .{}),
ShaderInitError.FragementCompilation => std.debug.panic("Could not compile fragment shaders!\n", .{}),
ShaderInitError.ShaderProgramLinking => std.debug.panic("Could not link shader program!\n", .{}),
};
var rect_vao: c_uint = undefined;
gl.glad_glGenVertexArrays.?(1, @ptrCast(&rect_vao));
gl.glad_glBindVertexArray.?(rect_vao);
const rect_verts: [4][3]f32 = .{ .{0.2, 0.2, 0.0}, .{0.8, 0.2, 0.0}, .{0.8, 0.4, 0.0}, .{0.2, 0.4, 0.0} };
const draw_indices: [2][3]c_uint = .{ .{0, 1, 3}, .{1, 2, 3} };
var r_vert_buffer: c_uint = undefined;
gl.glad_glGenBuffers.?(1, &r_vert_buffer);
gl.glad_glBindBuffer.?(gl.GL_ARRAY_BUFFER, r_vert_buffer);
gl.glBufferData(gl.GL_ARRAY_BUFFER, 2 * 3 * @sizeOf(f32), @ptrCast(&rect_verts), gl.GL_STATIC_DRAW);
// gl.glad_glBindBuffer.?(0);
var element_buffer: c_uint = undefined;
gl.glad_glGenBuffers.?(1, &element_buffer);
gl.glad_glBindBuffer.?(gl.GL_ELEMENT_ARRAY_BUFFER, element_buffer);
gl.glBufferData(gl.GL_ELEMENT_ARRAY_BUFFER, 2 * 3 * @sizeOf(c_uint), @ptrCast(&draw_indices), gl.GL_STATIC_DRAW);
// gl.glad_glBindBuffer.?(0);
gl.glEnableVertexAttribArray(0);
// ----- Simple Triangle ------
const verticies: [3][3]f32 = .{ .{-0.5, -0.5, 0.0}, .{0.5, -0.5, 0.0}, .{0.0, 0.5, 0.0} };
var vbo: gl.GLuint = undefined;
// Vertex array object
var vao: c_uint = undefined;
gl.glad_glGenVertexArrays.?(1, @ptrCast(&vao));
gl.glad_glBindVertexArray.?(vao);
// vertex buffer object
var vbo: c_uint = undefined;
gl.glad_glGenBuffers.?(1, &vbo);
std.debug.print("buffer id: '{d}'\n", .{ vbo });
gl.glad_glBindBuffer.?(gl.GL_ARRAY_BUFFER, vbo);
// type of buffer, size of memory being inserted, the data to be loaded, how the GPU handles the memory
// STREAM - write once, used a few times, STATIC - set once, used many times, DYNAMIC - changed a lot
// used many times
gl.glBufferData(gl.GL_ARRAY_BUFFER, 4 * 3 * @sizeOf(f32), @ptrCast(&verticies), gl.GL_STATIC_DRAW);
// 0 for location=0 from shader
// 3 for number of attributes per stride,
// the type of data
// if we want it to be normalized
// offset of start of data
// The target virtual buffer object is defined by the current state from glVertexAttribPointer
gl.glVertexAttribPointer(0, 3, gl.GL_FLOAT, gl.GL_FALSE, 3 * @sizeOf(f32), @ptrCast(&0));
gl.glEnableVertexAttribArray(0);
gl.glad_glBindVertexArray.?(0);
// ------ END Simple Triangle ------
std.debug.print("Vertex buffer assigned\n", .{});
var gl_err: gl.GLenum = 0;
gl.glDisable(gl.GL_CULL_FACE);
while(gl.glfwWindowShouldClose(window) == 0)
{
@ -65,10 +141,39 @@ pub fn main() void {
gl.glClearColor(0.2, 0.3, 0.4, 0.5); // state setting, follo wed by state using
gl.glClear(gl.GL_COLOR_BUFFER_BIT); // color buffer, depth buffer, and stencil buffer
gl.glUseProgram(shaderProgram);
gl.glad_glBindVertexArray.?(vao);
gl.glad_glBindBuffer.?(gl.GL_ARRAY_BUFFER, vbo);
// offset into vertexes, and count
// gl.glDrawArrays(gl.GL_TRIANGLES, 0, 3);
gl_err = gl.glGetError();
if (gl_err > 0) {
std.debug.print("There was an opengl error: {d}", .{gl_err});
gl_err = 0;
}
gl.glad_glBindVertexArray.?(rect_vao);
gl.glad_glBindBuffer.?(gl.GL_ARRAY_BUFFER, r_vert_buffer);
gl.glad_glBindBuffer.?(gl.GL_ELEMENT_ARRAY_BUFFER, element_buffer);
gl.glDrawElements(gl.GL_TRIANGLES, 6, gl.GL_UNSIGNED_INT, null);
gl_err = gl.glGetError();
if (gl_err > 0) {
std.debug.print("There was an opengl error: {d}", .{gl_err});
gl_err = 0;
}
// This swaps the "displayed" buffer with the "rendering" buffer
gl.glfwSwapBuffers(window);
}
gl.glDeleteVertexArrays(1, &vao);
gl.glDeleteBuffers(1, &vbo);
gl.glDeleteProgram(shaderProgram);
gl.glfwTerminate();
}
@ -82,3 +187,47 @@ fn handle_input(window: *gl.GLFWwindow) void {
gl.glfwSetWindowShouldClose(window, 1);
}
}
fn init_shader_program(vertex_shader: *const c_uint, frag_shader: *const c_uint, program: *const c_uint) ShaderInitError!void {
var success: c_int = undefined;
var infoLog: [512:0]u8 = undefined;
gl.glShaderSource(vertex_shader.*, 1, &vertexShaderSource, null);
gl.glCompileShader(vertex_shader.*);
gl.glGetShaderiv(vertex_shader.*, gl.GL_COMPILE_STATUS, &success);
std.debug.print("Vertex Shader compiled\n", .{});
if (success == 0) {
std.debug.print("Shader compile failed!\n", .{});
gl.glGetShaderInfoLog(vertex_shader.*, 512, null, &infoLog);
std.debug.print("Error Log: {s}\n", .{infoLog});
return ShaderInitError.VertexCompilation;
}
gl.glShaderSource(frag_shader.*, 1, &fragementShaderSource, null);
gl.glCompileShader(frag_shader.*);
gl.glGetShaderiv(frag_shader.*, gl.GL_COMPILE_STATUS, &success);
std.debug.print("Fragment Shader compiled\n", .{});
if (success == 0) {
std.debug.print("Shader compile failed!\n", .{});
gl.glGetShaderInfoLog(frag_shader.*, 512, null, &infoLog);
std.debug.print("Error Log: {s}\n", .{infoLog});
return ShaderInitError.FragementCompilation;
}
gl.glAttachShader(program.*, vertex_shader.*);
gl.glAttachShader(program.*, frag_shader.*);
gl.glLinkProgram(program.*);
std.debug.print("Shader Linking Complete\n", .{});
gl.glGetProgramiv(program.*, gl.GL_LINK_STATUS, &success);
if (success == 0) {
std.debug.print("Shader linking failed!\n", .{});
gl.glGetProgramInfoLog(program.*, 512, null, &infoLog);
std.debug.print("Error Log: {s}", .{infoLog});
return ShaderInitError.ShaderProgramLinking;
}
gl.glDeleteShader(vertex_shader.*);
gl.glDeleteShader(frag_shader.*);
std.debug.print("Shader program selected, cleaned up compiled shaders\n", .{});
}