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authorYaroslav de la Peña Smirnov <yps@yaroslavps.com>2024-09-21 23:40:37 +0300
committerYaroslav de la Peña Smirnov <yps@yaroslavps.com>2024-09-21 23:40:37 +0300
commit44a1263cbbe6a19f796d6fb05e74396703482340 (patch)
treed3a7604d195f73c43940afb2cc5de0ccf01cd108 /src
parentf880b428ff5735afd5d625645443474a03eb315c (diff)
downloadzigway-44a1263cbbe6a19f796d6fb05e74396703482340.tar.gz
zigway-44a1263cbbe6a19f796d6fb05e74396703482340.zip
gl: rgb trianglegl/rgb-triangle
Diffstat (limited to 'src')
-rw-r--r--src/main.zig46
1 files changed, 34 insertions, 12 deletions
diff --git a/src/main.zig b/src/main.zig
index 13ff58b..8b9f927 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -17,20 +17,24 @@ const egl = @import("egl.zig");
const vertex_shader_src: [*c]const u8 =
\\#version 330 core
\\layout (location = 0) in vec3 pos;
+ \\layout (location = 1) in vec4 in_color;
+ \\out vec4 color;
\\
\\void main()
\\{
+ \\ color = in_color;
\\ gl_Position = vec4(pos.x, pos.y, pos.z, 1.0);
\\}
;
const frag_shader_src: [*c]const u8 =
\\#version 330 core
+ \\in vec4 color;
\\out vec4 frag_color;
\\
\\void main()
\\{
- \\ frag_color = vec4(1.0f, 0.2f, 0.2f, 1.0f);
+ \\ frag_color = vec4(color);
\\}
;
@@ -117,19 +121,24 @@ pub const Window = struct {
/// OpenGl triangle shader program
shader_prog: c_uint = undefined,
/// Triangle vertices
- vertices: [12]f32 = .{
+ vertices: [9]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
+ 0.5, -0.5, 0.0, // br
+ 0.0, 0.5, 0.0, // t
+ },
+ colors: [12]f32 = .{
+ 1.0, 0.0, 0.0, 1.0,
+ 0.0, 1.0, 0.0, 1.0,
+ 0.0, 0.0, 1.0, 1.0,
},
/// Triangles indices
- indices: [6]c_uint = .{
+ indices: [3]c_uint = .{
0, 1, 2,
- 2, 3, 0,
},
/// OpenGL vertex buffer object
vbo: c_uint = undefined,
+ /// OpenGL color vbo
+ cbo: c_uint = undefined,
/// OpenGL vertex array object
vao: c_uint = undefined,
// OpenGL element buffer object
@@ -194,6 +203,7 @@ pub const Window = struct {
c.glGenVertexArrays(1, &win.vao);
c.glGenBuffers(1, &win.vbo);
+ c.glGenBuffers(1, &win.cbo);
c.glGenBuffers(1, &win.ebo);
c.glBindVertexArray(win.vao);
@@ -206,6 +216,20 @@ pub const Window = struct {
c.GL_STATIC_DRAW,
);
+ c.glVertexAttribPointer(0, 3, c.GL_FLOAT, c.GL_FALSE, 3 * @sizeOf(f32), null);
+ c.glEnableVertexAttribArray(0);
+
+ c.glBindBuffer(c.GL_ARRAY_BUFFER, win.cbo);
+ c.glBufferData(
+ c.GL_ARRAY_BUFFER,
+ @sizeOf(@TypeOf(win.colors)),
+ &win.colors,
+ c.GL_STATIC_DRAW,
+ );
+
+ c.glVertexAttribPointer(1, 3, c.GL_FLOAT, c.GL_FALSE, 4 * @sizeOf(f32), null);
+ c.glEnableVertexAttribArray(1);
+
c.glBindBuffer(c.GL_ELEMENT_ARRAY_BUFFER, win.ebo);
c.glBufferData(
c.GL_ELEMENT_ARRAY_BUFFER,
@@ -214,9 +238,6 @@ pub const Window = struct {
c.GL_STATIC_DRAW,
);
- c.glVertexAttribPointer(0, 3, c.GL_FLOAT, c.GL_FALSE, 3 * @sizeOf(f32), null);
- c.glEnableVertexAttribArray(0);
-
c.glBindBuffer(c.GL_ARRAY_BUFFER, 0);
c.glBindVertexArray(0);
@@ -251,12 +272,12 @@ pub const Window = struct {
pub fn drawFrame(win: *Window) !void {
try egl_display.swapInterval(0);
- c.glClearColor(0, 0.5, 1, 1);
+ c.glClearColor(0, 0.05, 0.15, 1);
c.glClear(c.GL_COLOR_BUFFER_BIT);
c.glUseProgram(win.shader_prog);
c.glBindVertexArray(win.vao);
- c.glDrawElements(c.GL_TRIANGLES, 6, c.GL_UNSIGNED_INT, null);
+ c.glDrawElements(c.GL_TRIANGLES, win.indices.len, c.GL_UNSIGNED_INT, null);
try egl_display.swapBuffers(win.egl_surface);
}
@@ -361,6 +382,7 @@ pub fn main() !void {
.{ .type = .red_size, .value = 8 },
.{ .type = .green_size, .value = 8 },
.{ .type = .blue_size, .value = 8 },
+ .{ .type = .alpha_size, .value = 8 },
.{ .type = .none, .value = 0 },
};
egl_display = try egl.Display.get(display);