feat(platform): draw fullscreen triangle instead of quad

This commit is contained in:
Rekai Nyangadzayi Musuka 2023-09-04 23:11:18 -05:00
parent 4c57f0b5f4
commit b9d4482531
3 changed files with 33 additions and 85 deletions

View File

@ -39,7 +39,7 @@ pub const Ui = struct {
if (SDL.SDL_Init(SDL.SDL_INIT_VIDEO | SDL.SDL_INIT_EVENTS | SDL.SDL_INIT_AUDIO) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_PROFILE_MASK, SDL.SDL_GL_CONTEXT_PROFILE_CORE) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MAJOR_VERSION, 3) < 0) panic();
if (SDL.SDL_GL_SetAttribute(SDL.SDL_GL_CONTEXT_MINOR_VERSION, 3) < 0) panic();
const window = SDL.SDL_CreateWindow(
window_title,
@ -90,20 +90,20 @@ pub const Ui = struct {
pub fn run(self: *Self, nds7_group: nds7.Group, nds9_group: nds9.Group) !void {
// TODO: Sort this out please
const objects = opengl_impl.createObjects();
defer gl.deleteBuffers(3, &[_]GLuint{ objects.vao, objects.vbo, objects.ebo });
const vao_id = opengl_impl.vao();
defer gl.deleteVertexArrays(1, &[_]GLuint{vao_id});
const top_tex = opengl_impl.createScreenTexture(nds9_group.bus.ppu.fb.top(.front));
const btm_tex = opengl_impl.createScreenTexture(nds9_group.bus.ppu.fb.btm(.front));
const top_out_tex = opengl_impl.createOutputTexture();
const btm_out_tex = opengl_impl.createOutputTexture();
const top_tex = opengl_impl.screenTex(nds9_group.bus.ppu.fb.top(.front));
const btm_tex = opengl_impl.screenTex(nds9_group.bus.ppu.fb.btm(.front));
const top_out_tex = opengl_impl.outTex();
const btm_out_tex = opengl_impl.outTex();
defer gl.deleteTextures(4, &[_]GLuint{ top_tex, top_out_tex, btm_tex, btm_out_tex });
const top_fbo = try opengl_impl.createFrameBuffer(top_out_tex);
const btm_fbo = try opengl_impl.createFrameBuffer(btm_out_tex);
const top_fbo = try opengl_impl.frameBuffer(top_out_tex);
const btm_fbo = try opengl_impl.frameBuffer(btm_out_tex);
defer gl.deleteFramebuffers(2, &[_]GLuint{ top_fbo, btm_fbo });
const prog_id = try opengl_impl.compileShaders();
const prog_id = try opengl_impl.program();
defer gl.deleteProgram(prog_id);
var event: SDL.SDL_Event = undefined;
@ -175,7 +175,7 @@ pub const Ui = struct {
defer gl.bindFramebuffer(gl.FRAMEBUFFER, 0);
gl.viewport(0, 0, nds_width, nds_height);
opengl_impl.drawScreenTexture(top_tex, prog_id, objects, nds9_group.bus.ppu.fb.top(.front));
opengl_impl.drawScreen(top_tex, prog_id, vao_id, nds9_group.bus.ppu.fb.top(.front));
}
{
@ -183,7 +183,7 @@ pub const Ui = struct {
defer gl.bindFramebuffer(gl.FRAMEBUFFER, 0);
gl.viewport(0, 0, nds_width, nds_height);
opengl_impl.drawScreenTexture(btm_tex, prog_id, objects, nds9_group.bus.ppu.fb.btm(.front));
opengl_impl.drawScreen(btm_tex, prog_id, vao_id, nds9_group.bus.ppu.fb.btm(.front));
}
const zgui_redraw = imgui.draw(&self.state, top_out_tex, btm_out_tex, nds9_group.cpu);
@ -213,44 +213,24 @@ fn panic() noreturn {
}
const opengl_impl = struct {
// zig fmt: off
const vertices: [32]f32 = [_]f32{
// Positions // Colours // Texture Coords
1.0, -1.0, 0.0, 1.0, 0.0, 0.0, 1.0, 1.0, // Top Right
1.0, 1.0, 0.0, 0.0, 1.0, 0.0, 1.0, 0.0, // Bottom Right
-1.0, 1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, // Bottom Left
-1.0, -1.0, 0.0, 1.0, 1.0, 0.0, 0.0, 1.0, // Top Left
};
const indices: [6]u32 = [_]u32{
0, 1, 3, // First Triangle
1, 2, 3, // Second Triangle
};
// zig fmt: on
const Objects = struct { vao: GLuint, vbo: GLuint, ebo: GLuint };
fn drawScreenTexture(tex_id: GLuint, prog_id: GLuint, ids: Objects, buf: []const u8) void {
fn drawScreen(tex_id: GLuint, prog_id: GLuint, vao_id: GLuint, buf: []const u8) void {
gl.bindTexture(gl.TEXTURE_2D, tex_id);
defer gl.bindTexture(gl.TEXTURE_2D, 0);
gl.texSubImage2D(gl.TEXTURE_2D, 0, 0, 0, nds_width, nds_height, gl.RGBA, gl.UNSIGNED_INT_8_8_8_8, buf.ptr);
// Bind VAO, EBO. VBO not bound
gl.bindVertexArray(ids.vao); // VAO
// Bind VAO
gl.bindVertexArray(vao_id); // VAO
defer gl.bindVertexArray(0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, ids.ebo); // EBO
defer gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0);
// Use compiled frag + vertex shader
gl.useProgram(prog_id);
defer gl.useProgram(0);
gl.drawElements(gl.TRIANGLES, 6, gl.UNSIGNED_INT, null);
gl.drawArrays(gl.TRIANGLE_STRIP, 0, 3);
}
fn compileShaders() !GLuint {
fn program() !GLuint {
const vert_shader = @embedFile("shader/pixelbuf.vert");
const frag_shader = @embedFile("shader/pixelbuf.frag");
@ -270,50 +250,22 @@ const opengl_impl = struct {
if (!shader.didCompile(fs)) return error.FragmentCompileError;
const program = gl.createProgram();
gl.attachShader(program, vs);
gl.attachShader(program, fs);
gl.linkProgram(program);
const prog = gl.createProgram();
gl.attachShader(prog, vs);
gl.attachShader(prog, fs);
gl.linkProgram(prog);
return program;
return prog;
}
// Returns the VAO ID since it's used in run()
fn createObjects() Objects {
fn vao() GLuint {
var vao_id: GLuint = undefined;
var vbo_id: GLuint = undefined;
var ebo_id: GLuint = undefined;
gl.genVertexArrays(1, &vao_id);
gl.genBuffers(1, &vbo_id);
gl.genBuffers(1, &ebo_id);
gl.bindVertexArray(vao_id);
defer gl.bindVertexArray(0);
gl.bindBuffer(gl.ARRAY_BUFFER, vbo_id);
defer gl.bindBuffer(gl.ARRAY_BUFFER, 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, ebo_id);
defer gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, 0);
gl.bufferData(gl.ARRAY_BUFFER, @sizeOf(@TypeOf(vertices)), &vertices, gl.STATIC_DRAW);
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, @sizeOf(@TypeOf(indices)), &indices, gl.STATIC_DRAW);
// Position
gl.vertexAttribPointer(0, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), null); // lmao
gl.enableVertexAttribArray(0);
// Colour
gl.vertexAttribPointer(1, 3, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), @ptrFromInt((3 * @sizeOf(f32))));
gl.enableVertexAttribArray(1);
// Texture Coord
gl.vertexAttribPointer(2, 2, gl.FLOAT, gl.FALSE, 8 * @sizeOf(f32), @ptrFromInt((6 * @sizeOf(f32))));
gl.enableVertexAttribArray(2);
return .{ .vao = vao_id, .vbo = vbo_id, .ebo = ebo_id };
return vao_id;
}
fn createScreenTexture(buf: []const u8) GLuint {
fn screenTex(buf: []const u8) GLuint {
var tex_id: GLuint = undefined;
gl.genTextures(1, &tex_id);
@ -328,7 +280,7 @@ const opengl_impl = struct {
return tex_id;
}
fn createOutputTexture() GLuint {
fn outTex() GLuint {
var tex_id: GLuint = undefined;
gl.genTextures(1, &tex_id);
@ -343,7 +295,7 @@ const opengl_impl = struct {
return tex_id;
}
fn createFrameBuffer(tex_id: GLuint) !GLuint {
fn frameBuffer(tex_id: GLuint) !GLuint {
var fbo_id: GLuint = undefined;
gl.genFramebuffers(1, &fbo_id);

View File

@ -1,7 +1,6 @@
#version 330 core
out vec4 frag_color;
in vec3 color;
in vec2 uv;
uniform sampler2D screen;

View File

@ -1,13 +1,10 @@
#version 330 core
layout (location = 0) in vec3 pos;
layout (location = 1) in vec3 in_color;
layout (location = 2) in vec2 in_uv;
out vec3 color;
out vec2 uv;
const vec2 pos[3] = vec2[3](vec2(-1.0f, -1.0f), vec2(-1.0f, 3.0f), vec2(3.0f, -1.0f));
const vec2 uvs[3] = vec2[3](vec2( 2.0f, 2.0f), vec2( 2.0f, 0.0f), vec2(0.0f, 2.0f));
void main() {
color = in_color;
uv = in_uv;
gl_Position = vec4(pos, 1.0);
uv = uvs[gl_VertexID];
gl_Position = vec4(pos[gl_VertexID], 0.0, 1.0);
}