1 files changed, 105 insertions, 0 deletions
diff --git a/shader.h b/shader.h
new file mode 100644
index 0000000..189225a
--- /dev/null
+++ b/shader.h
@@ -0,0 +1,105 @@
+shader_t compile_gl_shader(u32 type, char **src)
+{
+	shader_t shader = {0};
+	shader.id = glCreateShader(type);
+	glShaderSource(shader.id, 1, (const char **)src, 0);
+	glCompileShader(shader.id);
+
+	i32 status;
+	glGetShaderiv(shader.id, GL_COMPILE_STATUS, &status);
+	if (status == GL_FALSE)
+		glGetShaderInfoLog(shader.id, MAX_SHADER_LOG, 0, shader.log);
+	else
+		snprintf(shader.log, MAX_SHADER_LOG, "compiled successfully");
+
+	return shader;
+}
+
+shader_t compile_gl_shader_file(u32 type, const char *filename)
+{
+	char *src;
+	shader_t shader = {0};
+
+	arena_t tmp = alloc_arena(0);
+	if (!sys_read_file(&tmp, &src, filename)) {
+		printf("error: failed to read: \"%s\"\n", filename);
+		release_arena(&tmp);
+		return shader;
+	}
+	shader = compile_gl_shader(type, &src);
+	release_arena(&tmp);
+
+	if (!shader.id)
+		printf("error: \"%s\": ", filename);
+	else
+		printf("info: \"%s\": ", filename);
+	printf("%s", shader.log);
+	printf("\n");
+
+	return shader;
+}
+
+shader_t load_gl_shader(const char *dir, const char *vert_filename, const char *geom_filename, const char *frag_filename)
+{
+	shader_t shader = {0};
+	shader.id = glCreateProgram();
+
+	char full_path[MAX_PATH];
+	shader_t vert;
+	if (vert_filename) {
+		snprintf(full_path, sizeof(full_path), "%s/%s", dir, vert_filename);
+		vert = compile_gl_shader_file(GL_VERTEX_SHADER, full_path);
+		glAttachShader(shader.id, vert.id);
+	}
+
+	shader_t geom;
+	if (geom_filename) {
+		snprintf(full_path, sizeof(full_path), "%s/%s", dir, geom_filename);
+		geom = compile_gl_shader_file(GL_GEOMETRY_SHADER, full_path);
+		glAttachShader(shader.id, geom.id);
+	}
+
+	shader_t frag;
+	if (frag_filename) {
+		snprintf(full_path, sizeof(full_path), "%s/%s", dir, frag_filename);
+		frag = compile_gl_shader_file(GL_FRAGMENT_SHADER, full_path);
+		glAttachShader(shader.id, frag.id);
+	}
+
+	i32 status;
+	glLinkProgram(shader.id);
+	glGetProgramiv(shader.id, GL_LINK_STATUS, &status);
+	if (status == GL_FALSE) {
+		glGetProgramInfoLog(shader.id, MAX_SHADER_LOG, 0, shader.log);
+		printf("error: failed to link shader program:\n%s", shader.log);
+	} else {
+		printf("info: shader linked successfuly\n\n");
+	}
+
+	if (vert_filename)
+		glDeleteShader(vert.id);
+	if (geom_filename)
+		glDeleteShader(geom.id);
+	if (frag_filename)
+		glDeleteShader(frag.id);
+
+	return shader;
+}
+
+void shader_set_v3(shader_t shader, const char *name, v3 vec)
+{
+	i32 location = glGetUniformLocation(shader.id, name);
+	glUniform3fv(location, 1, (f32 *)&vec);
+}
+
+void shader_set_v4(shader_t shader, const char *name, v4 vec)
+{
+	i32 location = glGetUniformLocation(shader.id, name);
+	glUniform4fv(location, 1, (f32 *)&vec);
+}
+
+void shader_set_mat4(shader_t shader, const char *name, mat4 mat)
+{
+	i32 location = glGetUniformLocation(shader.id, name);
+	glUniformMatrix4fv(location, 1, 0, (f32 *)&mat);
+}