1 files changed, 101 insertions, 0 deletions
diff --git a/in_practice/breakout/shader.c b/in_practice/breakout/shader.c
new file mode 100644
index 0000000..2fff3c4
--- /dev/null
+++ b/in_practice/breakout/shader.c
@@ -0,0 +1,101 @@
+#include "shader.h"
+#include "sys.h"
+
+#include <GL/glew.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+shader_t shaders[MAX_SHADERS] = {0};
+
+static u32 compile_shader(GLenum type, const char *dir, const char *filename)
+{
+	char path[512] = {0};
+	snprintf(path, 512, "%s/%s", (dir ? dir : "."), filename);
+	const char *src = (const char *)read_entire_file(path);
+	if (!src) {
+		info("failed to read the file \"%s\"", path);
+		return 0;
+	}
+	u32 id = glCreateShader(type);
+	glShaderSource(id, 1, &src, 0);
+	free((void *)src);
+	glCompileShader(id);
+	i32 status;
+	glGetShaderiv(id, GL_COMPILE_STATUS, &status);
+	if (status == GL_FALSE) {
+		char log[512];
+		glGetShaderInfoLog(id, 512, 0, log);
+		info("failed to compile \"%s\"\n%s", path, log);
+	} else {
+		info("\"%s\" compiled successfully", path);
+	}
+	return id;
+}
+
+u32 load_shader(const char *dir, const char *vertex_filename, const char *fragment_filename, const char *geometry_filename, const char *name)
+{
+	if (get_shader(name)) {
+		info("shader \"%s\" already exist", name);
+		return 0;
+	}
+	u32 id = glCreateProgram();
+	u32 vert = compile_shader(GL_VERTEX_SHADER, dir, vertex_filename);
+	glAttachShader(id, vert);
+	u32 frag = compile_shader(GL_FRAGMENT_SHADER, dir, fragment_filename);
+	glAttachShader(id, frag);
+	u32 geom = 0;
+	if (geometry_filename) {
+		geom = compile_shader(GL_GEOMETRY_SHADER, dir, geometry_filename);
+		glAttachShader(id, geom);
+	}
+	glLinkProgram(id);
+	i32 success;
+	glGetProgramiv(id, GL_LINK_STATUS, &success);
+	if (success == GL_FALSE) {
+		char log[512];
+		glGetProgramInfoLog(id, 512, 0, log);
+		info("failed to link shader:\n%s", log);
+	}
+	glDeleteShader(vert);
+	glDeleteShader(frag);
+	if (geometry_filename)
+		glDeleteShader(geom);
+	shader_t shader = {id, name};
+	i32 i;
+	for (i = 0; i < MAX_SHADERS; i++) {
+		if (!shaders[i].id) {
+			shaders[i] = shader;
+			return id;
+		}
+	}
+	info("shader limit (%d) reached", MAX_SHADERS);
+	glDeleteProgram(id);
+	return 0;
+}
+
+u32 get_shader(const char *name)
+{
+	for (i32 i = 0; i < MAX_SHADERS; i++)
+		if (shaders[i].name && strstr(shaders[i].name, name))
+			return shaders[i].id;
+	return 0;
+}
+
+void uniform_f32(u32 id, const char *name, f32 v)
+{
+	u32 loc = glGetUniformLocation(id, name);
+	glUniform1f(loc, v);
+}
+
+void uniform_v3(u32 id, const char *name, v3 v)
+{
+	u32 loc = glGetUniformLocation(id, name);
+	glUniform3fv(loc, 1, (const f32 *)&v);
+}
+
+void uniform_mat(u32 id, const char *name, mat m)
+{
+	u32 loc = glGetUniformLocation(id, name);
+	glUniformMatrix4fv(loc, 1, 0, (const f32 *)&m);
+}