2-pass rendering working w/ fixed resolution + upscaling

6 files changed, 39 insertions, 24 deletions

diff --git a/consts.h b/consts.h
new file mode 100644
index 0000000..08a1801
--- /dev/null
+++ b/consts.h
@@ -0,0 +1,7 @@
+#ifndef CONSTS_H
+#define CONSTS_H
+
+#define RES_H 800
+#define RES_V 600
+
+#endif
diff --git a/main.c b/main.c
index 50cf16d..b247c04 100644
--- a/main.c
+++ b/main.c
@@ -2,13 +2,14 @@
 #include <GL/glew.h>
 #include <GLFW/glfw3.h>
 
+#include "consts.h"
 #include "shader.h"
 #include "die.h"
 #include "uniform.h"
 
 #include "fill_vert.h"
-#include "visuals_frag.h"
-#include "output_frag.h"
+#include "pass1_frag.h"
+#include "pass2_frag.h"
 
 void resize_handler(GLFWwindow* window, int width, int height) {
 	glViewport(0, 0, width, height);
@@ -24,8 +25,7 @@ GLFWwindow* init_window() {
 	glfwWindowHint(GLFW_RESIZABLE, GL_FALSE);
 
 	// initialize window
-	int width = 800, height = 600; // default size
-	GLFWwindow* window = glfwCreateWindow(width, height, "vis", NULL, NULL);
+	GLFWwindow* window = glfwCreateWindow(RES_H, RES_V, "vis", NULL, NULL);
 	if (window == NULL)
 		die("error: could not create window\n");
 	glfwMakeContextCurrent(window);
@@ -70,17 +70,17 @@ int main(int argc, char** argv) {
 
 	init_tri();
 
-	GLuint visuals = link_shaders(
+	GLuint pass1 = link_shaders(
 		vert_shader(fill_vert, fill_vert_size),
-		frag_shader(visuals_frag, visuals_frag_size)
+		frag_shader(pass1_frag, pass1_frag_size)
 	);
-	uniforms_t * visuals_uniforms = init_uniforms(visuals, window);
+	uniforms_t * pass1_uniforms = init_uniforms(pass1, window);
 
-	GLuint output = link_shaders(
+	GLuint pass2 = link_shaders(
 		vert_shader(fill_vert, fill_vert_size),
-		frag_shader(output_frag, output_frag_size)
+		frag_shader(pass2_frag, pass2_frag_size)
 	);
-	uniforms_t * output_uniforms = init_uniforms(output, window);
+	uniforms_t * pass2_uniforms = init_uniforms(pass2, window);
 
 	GLuint fbo;
 	glGenFramebuffers(1, &fbo);
@@ -90,24 +90,26 @@ int main(int argc, char** argv) {
 	glGenTextures(1, &last_frame);
 	glBindTexture(GL_TEXTURE_2D, last_frame);
 	// todo: what to do when the size changes?
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 800, 600, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, RES_H, RES_V, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 	glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, last_frame, 0);
 	if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
 		die("can't initialize framebuffer??\n");
 	glBindFramebuffer(GL_FRAMEBUFFER, 0);
 
-	glUseProgram(visuals);
 
 	// main draw loop
 	while (!glfwWindowShouldClose(window)) {
 		glfwPollEvents();
 
-		update_uniforms(visuals_uniforms);
+		glUseProgram(pass1);
+		update_uniforms(pass1_uniforms);
 		glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 		glDrawArrays(GL_TRIANGLES, 0, 3);
 
+		glUseProgram(pass2);
+		update_uniforms(pass2_uniforms);
 		glBindFramebuffer(GL_FRAMEBUFFER, 0);
 		glDrawArrays(GL_TRIANGLES, 0, 3);
 
diff --git a/makefile b/makefile
index d22eaec..d1383fb 100644
--- a/makefile
+++ b/makefile
@@ -15,15 +15,15 @@ all: main FORCE
 main: main.o
 main: die.o
 main: shader.o
-main: visuals_frag.o
+main: pass1_frag.o
 main: fill_vert.o
-main: output_frag.o
+main: pass2_frag.o
 main: uniform.o
 
 # fix compile order
 main.o: fill_vert.h
-main.o: visuals_frag.h
-main.o: output_frag.h
+main.o: pass1_frag.h
+main.o: pass2_frag.h
 
 %.s %.h &: %.spv
 	./blob $< $*
diff --git a/visuals.frag b/pass1.frag
index 35f9a6a..725c854 100644
--- a/visuals.frag
+++ b/pass1.frag
@@ -1,12 +1,15 @@
 #version 460 core
 
+#include "consts.h"
+
 out vec4 color;
 in vec4 gl_FragCoord;
 
 uniform float time;
-uniform ivec2 window;
 uniform sampler2D buf;
 
+ivec2 window = ivec2(RES_H, RES_V);
+
 void main() {
 	vec2 point = vec2(sin(time), cos(time)) * 0.7;
 	point.x *= float(window.y) / float(window.x); // adjust for aspect ratio
@@ -17,6 +20,6 @@ void main() {
 	if (length(gl_FragCoord.xy - point) < r)
 		color = vec4(1.0);
 
-	color += texture(buf, gl_FragCoord.xy / window.xy) * 0.90;
+	color += texture(buf, gl_FragCoord.xy / window.xy) * 0.95;
 }
 
diff --git a/output.frag b/pass2.frag
index df4d103..3193cb0 100644
--- a/output.frag
+++ b/pass2.frag
@@ -1,5 +1,7 @@
 #version 460 core
 
+#include "consts.h"
+
 out vec4 color;
 in vec4 gl_FragCoord;
 
@@ -7,6 +9,7 @@ uniform ivec2 window;
 uniform sampler2D buf;
 
 void main() {
-	color = texture(buf, gl_FragCoord.xy / window.xy);
+	vec2 uv = gl_FragCoord.xy / window.xy;
+	color = texture(buf, uv);
 }
 
diff --git a/uniform.c b/uniform.c
index a6a7772..dbfd0d0 100644
--- a/uniform.c
+++ b/uniform.c
@@ -19,7 +19,7 @@ uniforms_t * init_uniforms(GLuint shader, GLFWwindow* _window) {
 	return uniforms;
 }
 
-/** @brief update `uniform float time` */
+//! update `uniform float time`
 static void update_u_time(GLuint u_time) {
 	struct timeval t;
 	gettimeofday(&t, NULL);
@@ -28,7 +28,7 @@ static void update_u_time(GLuint u_time) {
 	glUniform1f(u_time, time);
 }
 
-/** @brief update `uniform ivec2 window` */
+//! update `uniform ivec2 window`
 static void update_u_window(GLuint u_window) {
 	int width, height;
 	glfwGetWindowSize(window, &width, &height);