From f880b428ff5735afd5d625645443474a03eb315c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Yaroslav=20de=20la=20Pe=C3=B1a=20Smirnov?=
<yps@yaroslavps.com>
Date: Sat, 21 Sep 2024 21:17:50 +0300
Subject: gl: square
---
src/main.zig | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
(limited to 'src')
diff --git a/src/main.zig b/src/main.zig
index 7543090..13ff58b 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -70,7 +70,7 @@ fn checkGlError(
const err = success == 0;
if (err) {
getLogFn(obj, 512, null, &gl_log);
- std.debug.print("Shader compilation error: {s}\n", .{gl_log});
+ std.debug.print("OpenGL shader error: {s}\n", .{gl_log});
}
return err;
}
@@ -117,11 +117,23 @@ pub const Window = struct {
/// OpenGl triangle shader program
shader_prog: c_uint = undefined,
/// Triangle vertices
- vertices: [9]f32,
+ vertices: [12]f32 = .{
+ -0.5, -0.5, 0.0, // bl
+ 0.5, -0.5, 0.0, // br
+ 0.5, 0.5, 0.0, // tr
+ -0.5, 0.5, 0.0, // tl
+ },
+ /// Triangles indices
+ indices: [6]c_uint = .{
+ 0, 1, 2,
+ 2, 3, 0,
+ },
/// OpenGL vertex buffer object
vbo: c_uint = undefined,
/// OpenGL vertex array object
vao: c_uint = undefined,
+ // OpenGL element buffer object
+ ebo: c_uint = undefined,
/// This window's title
title: [*:0]const u8,
/// Width in pixels
@@ -147,11 +159,6 @@ pub const Window = struct {
.allocator = allocator,
.wl_surface = try compositor.createSurface(),
.title = title,
- .vertices = .{
- -0.5, -0.5, 0.0,
- 0.5, -0.5, 0.0,
- 0.0, 0.5, 0.0,
- },
};
win.xdg_surface = try wm_base.getXdgSurface(win.wl_surface);
errdefer win.xdg_surface.destroy();
@@ -187,6 +194,7 @@ pub const Window = struct {
c.glGenVertexArrays(1, &win.vao);
c.glGenBuffers(1, &win.vbo);
+ c.glGenBuffers(1, &win.ebo);
c.glBindVertexArray(win.vao);
@@ -198,6 +206,14 @@ pub const Window = struct {
c.GL_STATIC_DRAW,
);
+ c.glBindBuffer(c.GL_ELEMENT_ARRAY_BUFFER, win.ebo);
+ c.glBufferData(
+ c.GL_ELEMENT_ARRAY_BUFFER,
+ @sizeOf(@TypeOf(win.indices)),
+ &win.indices,
+ c.GL_STATIC_DRAW,
+ );
+
c.glVertexAttribPointer(0, 3, c.GL_FLOAT, c.GL_FALSE, 3 * @sizeOf(f32), null);
c.glEnableVertexAttribArray(0);
@@ -240,7 +256,7 @@ pub const Window = struct {
c.glUseProgram(win.shader_prog);
c.glBindVertexArray(win.vao);
- c.glDrawArrays(c.GL_TRIANGLES, 0, 3);
+ c.glDrawElements(c.GL_TRIANGLES, 6, c.GL_UNSIGNED_INT, null);
try egl_display.swapBuffers(win.egl_surface);
}
--
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