1 files changed, 109 insertions, 0 deletions
diff --git a/in_practice/breakout/post_processor.c b/in_practice/breakout/post_processor.c
new file mode 100644
index 0000000..70691c2
--- /dev/null
+++ b/in_practice/breakout/post_processor.c
@@ -0,0 +1,109 @@
+#include "post_processor.h"
+#include "sys.h"
+#include "shader.h"
+#include "texture.h"
+
+#include <GL/glew.h>
+
+struct post_processor init_post_processor(i32 width, i32 height, u32 shader)
+{
+	struct post_processor processor = {0};
+	processor.width = width;
+	processor.height = height;
+	glGenFramebuffers(1, &processor.msfbo);
+	glGenFramebuffers(1, &processor.fbo);
+	glGenRenderbuffers(1, &processor.rbo);
+	glBindFramebuffer(GL_FRAMEBUFFER, processor.msfbo);
+	glBindRenderbuffer(GL_RENDERBUFFER, processor.rbo);
+	glRenderbufferStorageMultisample(GL_RENDERBUFFER, 4, GL_RGB, width, height);
+	glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, processor.rbo);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		die("failed to create msfbo");
+	glBindRenderbuffer(GL_RENDERBUFFER, 0);
+	glBindFramebuffer(GL_FRAMEBUFFER, processor.fbo);
+	gl_texture_t texture = (gl_texture_t)default_texture;
+	generate_texture(&texture, width, height, 0);
+	processor.texture = texture.id;
+	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, processor.texture, 0);
+	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
+		die("failed to create fbo");
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+	u32 vbo;
+	f32 vertices[] = {
+		-1.0f, -1.0f, 0.0f, 0.0f,
+		1.0f,  1.0f, 1.0f, 1.0f,
+		-1.0f,  1.0f, 0.0f, 1.0f,
+		-1.0f, -1.0f, 0.0f, 0.0f,
+		1.0f, -1.0f, 1.0f, 0.0f,
+		1.0f,  1.0f, 1.0f, 1.0f
+	};
+	glGenBuffers(1, &vbo);
+	glBindBuffer(GL_ARRAY_BUFFER, vbo);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
+	glGenVertexArrays(1, &processor.vao);
+	glBindVertexArray(processor.vao);
+	glEnableVertexAttribArray(0);
+	glVertexAttribPointer(0, 4, GL_FLOAT, GL_FALSE, 4 * sizeof(f32), 0);
+	glBindVertexArray(0);
+	glBindBuffer(GL_ARRAY_BUFFER, 0);
+	processor.shader = shader;
+	glUseProgram(processor.shader);
+	uniform_i32(processor.shader, "colorbuffer", 0);
+	f32 offset = 1.0f / 300.0f;
+	f32 offsets[] = {
+		-offset, offset, /* top-left */
+		0.0f, offset, /* top-center */
+		offset, offset, /* top-right */
+		-offset, 0.0f, /* center-left */
+		0.0f, 0.0f, /* center */
+		offset, 0.0f, /* center-right */
+		-offset, -offset, /* bottom-left */
+		0.0f, -offset, /* bottom-center */
+		offset, -offset /* bottom-right */
+	};
+	glUniform2fv(glGetUniformLocation(processor.shader, "offsets"), 9, offsets);
+	i32 edge_kernel[] = {
+		-1, -1, -1,
+		-1,  8, -1,
+		-1, -1, -1
+	};
+	glUniform1iv(glGetUniformLocation(processor.shader, "edge_kernel"), 9, edge_kernel);
+	f32 blur_kernel[] = {
+		1.0f / 16.0f, 2.0f / 16.0f, 1.0f / 16.0f,
+		2.0f / 16.0f, 4.0f / 16.0f, 2.0f / 16.0f,
+		1.0f / 16.0f, 2.0f / 16.0f, 1.0f / 16.0f
+	};
+	glUniform1fv(glGetUniformLocation(processor.shader, "blur_kernel"), 9, blur_kernel);
+	glUseProgram(0);
+	return processor;
+}
+
+void begin_render(struct post_processor processor)
+{
+	glBindFramebuffer(GL_FRAMEBUFFER, processor.msfbo);
+	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+	glClear(GL_COLOR_BUFFER_BIT);
+}
+
+void end_render(struct post_processor processor)
+{
+	glBindFramebuffer(GL_READ_FRAMEBUFFER, processor.msfbo);
+	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, processor.fbo);
+	glBlitFramebuffer(0, 0, processor.width, processor.height, 0, 0, processor.width, processor.height, GL_COLOR_BUFFER_BIT, GL_NEAREST);
+	glBindFramebuffer(GL_FRAMEBUFFER, 0);
+}
+
+void render_post(struct post_processor processor, f32 time)
+{
+	glUseProgram(processor.shader);
+	uniform_f32(processor.shader, "time", time);
+	uniform_i32(processor.shader, "confuse", processor.confuse);
+	uniform_i32(processor.shader, "chaos", processor.chaos);
+	uniform_i32(processor.shader, "shake", processor.shake);
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, processor.texture);
+	glBindVertexArray(processor.vao);
+	glDrawArrays(GL_TRIANGLES, 0, 6);
+	glBindVertexArray(0);
+	glUseProgram(0);
+}