Restructure glslview/glslwrite code

1 files changed, 144 insertions, 0 deletions

diff --git a/glslwrite.c b/glslwrite.c
new file mode 100644
index 0000000..e9f746a
--- /dev/null
+++ b/glslwrite.c
@@ -0,0 +1,144 @@
+/*
+  Copyright (c) 2016, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "common.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+
+#include <png.h>
+
+#include <GL/glew.h>
+
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_opengl.h>
+
+
+void extra_load(GLuint program) {
+}
+
+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, (unsigned)current_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*(height-1-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);
+}
+
+int main(int argc, char *argv[]) {
+	if (argc != 3) {
+		fprintf(stderr, "Usage: glslwrite <shader> <output directory>\n");
+		exit(1);
+	}
+
+	SDL_Init(SDL_INIT_VIDEO);
+
+	SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
+	SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
+	SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
+	SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
+
+	SDL_Window *window = SDL_CreateWindow("glslwrite", 0, 0, 800, 800, SDL_WINDOW_OPENGL|SDL_WINDOW_RESIZABLE);
+	SDL_GLContext ctx = SDL_GL_CreateContext(window);
+
+	filename = argv[1];
+	init();
+	load();
+
+	while (true) {
+		SDL_Event e;
+
+		while (SDL_PollEvent(&e)) {
+			switch (e.type) {
+			case SDL_KEYDOWN:
+				switch (e.key.keysym.sym) {
+
+				case SDLK_ESCAPE:
+					goto quit;
+				}
+				break;
+
+			case SDL_QUIT:
+				goto quit;
+			}
+		}
+
+		int width, height;
+		SDL_GetWindowSize(window, &width, &height);
+
+		render(width, height);
+		SDL_GL_SwapWindow(window);
+
+		savePNG(width, height, argv[2]);
+		current_time += 20;
+	}
+
+ quit:
+	SDL_GL_DeleteContext(ctx);
+	SDL_DestroyWindow(window);
+	SDL_Quit();
+
+	return 0;
+}