Unify glwlview and glslwrite code

3 files changed, 92 insertions, 222 deletions

diff --git a/Makefile b/Makefile
index 0023a99..9e5304e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 all : glslview glslwrite
 
 glslview : glslview.c
-	gcc -o glslview glslview.c -lSDL2 -lGL -lGLEW -Wall
+	$(CC) -o $@ $^ -lSDL2 -lGL -lGLEW -Wall
 
-glslwrite : glslwrite.c
-	gcc -o glslwrite glslwrite.c -lSDL2 -lpng -lGL -lGLEW -Wall
+glslwrite : glslview.c
+	$(CC) -o $@ $^ -DGLSLWRITE -lSDL2 -lpng -lGL -lGLEW -Wall
diff --git a/glslview.c b/glslview.c
index c78bd7d..940c30d 100644
--- a/glslview.c
+++ b/glslview.c
@@ -1,16 +1,25 @@
 #include <stdbool.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <unistd.h>
 
+#ifdef GLSLWRITE
+# include <png.h>
+#endif
+
 #include <GL/glew.h>
 
 #include <SDL2/SDL.h>
 #include <SDL2/SDL_opengl.h>
 
 
+#ifdef GLSLWRITE
+static unsigned frame_time = 0;
+#endif
+
 
-static GLint time;
-static GLint res;
+static GLint time_loc;
+static GLint res_loc;
 
 
 static char * readfile(const char *filename) {
@@ -88,22 +97,71 @@ static void init(char *filename) {
         printProgramInfoLog(program);
 
         glBindFragDataLocation(program, 0, "fragColor");
-        time = glGetUniformLocation(program, "time");
-        res = glGetUniformLocation(program, "res");
+        time_loc = glGetUniformLocation(program, "time");
+        res_loc = glGetUniformLocation(program, "res");
 
         glUseProgram(program);
+}
 
+#ifdef GLSLWRITE
+static void savePNG(int width, int height, const char *output_dir) {
+        uint8_t pixels[width*height*4];
+        glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, pixels);
 
-}
+        char filename[strlen(output_dir) + 20];
+        snprintf(filename, sizeof(filename), "%s/%010u.png", output_dir, frame_time);
+
+        FILE *f = fopen(filename, "wb");
+	if (!f) {
+                fprintf(stderr, "unable to open PNG file\n");
+                exit(1);
+        }
+
+	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr) {
+                fprintf(stderr, "unable to open PNG file\n");
+                exit(1);
+        }
+
+        png_set_swap_alpha(png_ptr);
+
+	png_infop info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr) {
+		fprintf(stderr, "unable to create PNG info struct\n");
+                exit(1);
+	}
+
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		fprintf(stderr, "unable to write PNG file\n");
+                exit(1);
+	}
+
+	png_init_io(png_ptr, f);
+
+	png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA,
+		     PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+	uint8_t *row_pointers[height];
+	for (size_t i = 0; i < height; i++)
+		row_pointers[i] = &pixels[4*i*width];
 
-static void render(SDL_Window *window) {
-        int width, height;
-        SDL_GetWindowSize(window, &width, &height);
+	png_set_rows(png_ptr, info_ptr, row_pointers);
+	png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
 
+	png_destroy_write_struct(&png_ptr, &info_ptr);
+	fclose(f);
+}
+#endif
+
+static void render(int width, int height) {
 	glViewport(0, 0, (GLsizei)width, (GLsizei)height);
 
-        glUniform1f(time, SDL_GetTicks());
-        glUniform2f(res, width, height);
+#ifdef GLSLWRITE
+        glUniform1f(time_loc, frame_time);
+#else
+        glUniform1f(time_loc, SDL_GetTicks());
+#endif
+        glUniform2f(res_loc, width, height);
 
 	glBegin(GL_QUADS);
 	glVertex2f(-1, -1);
@@ -112,21 +170,30 @@ static void render(SDL_Window *window) {
 	glVertex2f(-1, 1);
 	glEnd();
 
-	SDL_GL_SwapWindow(window);
+#ifdef GLSLWRITE
+        frame_time += 20;
+#endif
 }
 
 
 int main(int argc, char *argv[]) {
 	bool running = true;
 
+#ifdef GLSLWRITE
+        if (argc != 3) {
+                fprintf(stderr, "Usage: glslwrite <shader> <output directory>\n");
+                exit(1);
+        }
+#else
         if (argc != 2) {
-                fprintf(stderr, "Usage: glslview <shader>\n");
+                fprintf(stderr, "Usage: glslview <shader> <output directory>\n");
                 exit(1);
         }
+#endif
 
 	SDL_Init(SDL_INIT_VIDEO);
 
-	SDL_Window *window = SDL_CreateWindow("glslview", 0, 0, 800, 800, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
+	SDL_Window *window = SDL_CreateWindow("glslwrite", 0, 0, 800, 800, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
         SDL_GL_CreateContext(window);
 
         init(argv[1]);
@@ -141,8 +208,15 @@ int main(int argc, char *argv[]) {
 			}
 		}
 
-		render(window);
-                //usleep(1);
+                int width, height;
+                SDL_GetWindowSize(window, &width, &height);
+
+		render(width, height);
+        	SDL_GL_SwapWindow(window);
+
+#ifdef GLSLWRITE
+                savePNG(width, height, argv[2]);
+#endif
 	}
 
 	return 0;
diff --git a/glslwrite.c b/glslwrite.c
deleted file mode 100644
index ebe81d4..0000000
--- a/glslwrite.c
+++ /dev/null
@@ -1,204 +0,0 @@
-#include <stdbool.h>
-#include <stdint.h>
-#include <stdio.h>
-#include <unistd.h>
-
-#include <png.h>
-
-#include <GL/glew.h>
-
-#include <SDL2/SDL.h>
-#include <SDL2/SDL_opengl.h>
-
-
-
-static unsigned frame_time = 0;
-
-
-static GLint time_loc;
-static GLint res_loc;
-
-
-static char * readfile(const char *filename) {
-        FILE *f = fopen(filename, "r");
-        if (!f)
-                return NULL;
-
-        size_t size = 1024;
-        char *buffer = malloc(size+1);
-        size_t count = 0, r;
-
-        do {
-                if (count == size) {
-                        size *= 2;
-                        buffer = realloc(buffer, size+1);
-                }
-
-                r = fread(buffer+count, 1, size-count, f);
-                count += r;
-        } while (r);
-
-        fclose(f);
-
-        buffer[count] = 0;
-
-        return buffer;
-}
-
-static void printShaderInfoLog(GLuint obj) {
-        GLint length = 0;
-
-        glGetShaderiv(obj, GL_INFO_LOG_LENGTH, &length);
-
-        if(length > 0) {
-                char log[length];
-
-                glGetShaderInfoLog(obj, sizeof(log), NULL, log);
-                fprintf(stderr, "%s\n", log);
-        }
-}
-
-static void printProgramInfoLog(GLuint obj) {
-        GLint length = 0;
-
-        glGetProgramiv(obj, GL_INFO_LOG_LENGTH, &length);
-
-        if(length > 0) {
-                char log[length];
-
-                glGetProgramInfoLog(obj, sizeof(log), NULL, log);
-                fprintf(stderr, "%s\n", log);
-        }
-}
-
-static void init(char *filename) {
-        glewInit();
-
-	glDisable(GL_DEPTH_TEST);
-
-        char *shader = readfile(filename);
-        if (!shader) {
-                fprintf(stderr, "Error: unable to read '%s'\n", filename);
-                exit(1);
-        }
-
-        GLuint frag = glCreateShader(GL_FRAGMENT_SHADER);
-        glShaderSource(frag, 1, (const GLchar **)&shader, NULL);
-        glCompileShader(frag);
-        printShaderInfoLog(frag);
-
-        GLuint program = glCreateProgram();
-        glAttachShader(program, frag);
-
-        glLinkProgram(program);
-        printProgramInfoLog(program);
-
-        glBindFragDataLocation(program, 0, "fragColor");
-        time_loc = glGetUniformLocation(program, "time");
-        res_loc = glGetUniformLocation(program, "res");
-
-        glUseProgram(program);
-}
-
-static void savePNG(uint8_t *pixels, int width, int height, const char *output_dir) {
-        char filename[strlen(output_dir) + 20];
-        snprintf(filename, sizeof(filename), "%s/%010u.png", output_dir, frame_time);
-
-        FILE *f = fopen(filename, "wb");
-	if (!f) {
-                fprintf(stderr, "unable to open PNG file\n");
-                exit(1);
-        }
-
-	png_structp png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
-	if (!png_ptr) {
-                fprintf(stderr, "unable to open PNG file\n");
-                exit(1);
-        }
-
-        png_set_swap_alpha(png_ptr);
-
-	png_infop info_ptr = png_create_info_struct(png_ptr);
-	if (!info_ptr) {
-		fprintf(stderr, "unable to create PNG info struct\n");
-                exit(1);
-	}
-
-	if (setjmp(png_jmpbuf(png_ptr))) {
-		fprintf(stderr, "unable to write PNG file\n");
-                exit(1);
-	}
-
-	png_init_io(png_ptr, f);
-
-	png_set_IHDR(png_ptr, info_ptr, width, height, 8, PNG_COLOR_TYPE_RGB_ALPHA,
-		     PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
-
-	uint8_t *row_pointers[height];
-	for (size_t i = 0; i < height; i++)
-		row_pointers[i] = &pixels[4*i*width];
-
-	png_set_rows(png_ptr, info_ptr, row_pointers);
-	png_write_png(png_ptr, info_ptr, PNG_TRANSFORM_IDENTITY, NULL);
-
-	png_destroy_write_struct(&png_ptr, &info_ptr);
-	fclose(f);
-}
-
-static void render(SDL_Window *window, const char *output_dir) {
-        int width, height;
-        SDL_GetWindowSize(window, &width, &height);
-
-	glViewport(0, 0, (GLsizei)width, (GLsizei)height);
-
-        glUniform1f(time_loc, frame_time);
-        glUniform2f(res_loc, width, height);
-
-	glBegin(GL_QUADS);
-	glVertex2f(-1, -1);
-	glVertex2f(1, -1);
-	glVertex2f(1, 1);
-	glVertex2f(-1, 1);
-	glEnd();
-
-	SDL_GL_SwapWindow(window);
-
-        uint8_t pixels[width*height*4];
-        glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, pixels);
-        savePNG(pixels, width, height, output_dir);
-
-        frame_time += 20;
-}
-
-
-int main(int argc, char *argv[]) {
-	bool running = true;
-
-        if (argc != 3) {
-                fprintf(stderr, "Usage: glslwrite <shader> <output directory>\n");
-                exit(1);
-        }
-
-	SDL_Init(SDL_INIT_VIDEO);
-
-	SDL_Window *window = SDL_CreateWindow("glslwrite", 0, 0, 800, 800, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
-        SDL_GL_CreateContext(window);
-
-        init(argv[1]);
-
-	while (running) {
-		SDL_Event e;
-
-		while( SDL_PollEvent(&e)) {
-			if(e.type == SDL_QUIT) {
-				running = false;
-                                break;
-			}
-		}
-
-		render(window, argv[2]);
-                //usleep(1);
-	}
-
-	return 0;
-}