Check for maximum texture and downscale image if bigger

This is temporary fix to prevent app entirely crashing or rendering
nothing. This has to be fixed eventually and work around it.

Author: SlouchyButton

src/rendering/image-processing.c

@@ -43,8 +43,8 @@ gpointer process_image(gpointer data) {
         self->con.image_data = calloc(image->width * image->height * 3, sizeof(uint16_t));
         memcpy(self->con.image_data, image->data, image->width * image->height * 3 * sizeof(uint16_t));
 
-        self->con.width = image->width;
-        self->con.height = image->height;
+        self->con.original_width = image->width;
+        self->con.original_height = image->height;
         self->con.bit_depth = image->bits;
     } else {
         fprintf(stderr, "Couldn't open file using libraw (errno: %d), trying gdk fallback\n",
@@ -63,18 +63,29 @@ gpointer process_image(gpointer data) {
         free(self->con.image_data);
         self->con.image_data = calloc(len, sizeof(guchar));
         memcpy(self->con.image_data, pix, len * sizeof(guchar));
-        self->con.width = gdk_pixbuf_get_width(pixbuf);
-        self->con.height = gdk_pixbuf_get_height(pixbuf);
+        self->con.original_width = gdk_pixbuf_get_width(pixbuf);
+        self->con.original_height = gdk_pixbuf_get_height(pixbuf);
         self->con.bit_depth = 8;
     }
     libraw_close(libraw_handle);
 
-    if (self->con.height > 1080) {
-        self->con.preview_height = self->con.height / 4;
-        self->con.preview_width = self->con.width / 4;
+
+    if (self->con.original_height > self->con.max_tex_size || self->con.original_width > self->con.max_tex_size) {
+        self->con.width = self->con.max_tex_size;
+        self->con.height = ((gdouble)self->con.original_height/self->con.original_width)*self->con.max_tex_size;
+        if (self->con.height > self->con.max_tex_size) {
+            self->con.width = ((gdouble)self->con.original_width/self->con.original_height)*self->con.max_tex_size;
+            self->con.height = self->con.max_tex_size;
+        }
+        printf("Image is bigger than what OGL can render new dimensions: %dx%d\n", self->con.width, self->con.height);
+    }
+
+    if (self->con.original_height > 1080) {
+        self->con.preview_height = self->con.original_height / 4;
+        self->con.preview_width = self->con.original_width / 4;
     } else {
-        self->con.preview_height = self->con.height;
-        self->con.preview_width = self->con.width;
+        self->con.preview_height = self->con.original_height;
+        self->con.preview_width = self->con.original_width;
     }
 
     self->con.texture_refresh_pending = true;

src/rendering/image-renderer.c

@@ -148,7 +148,7 @@ void refresh_textures(RendererControl* con) {
     // won't render correctly
     glBindTexture(GL_TEXTURE_2D, con->tex_base);
         glTexImage2D(GL_TEXTURE_2D, 0, con->bit_depth == 16 ? GL_RGB16 : GL_RGB8, 
-            con->width, con->height, 0, GL_RGB, 
+            con->original_width, con->original_height, 0, GL_RGB, 
             con->bit_depth == 16 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_BYTE, con->image_data);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
@@ -251,6 +251,9 @@ void realize(GtkWidget *widget, RendererControl* con) {
     prepare_textures(con);
 
     printf("Initialized OpenGL\n");
+    con->max_tex_size = 0;
+    glGetIntegerv(GL_MAX_3D_TEXTURE_SIZE, &con->max_tex_size);
+    printf("Max texture size: %d\n", con->max_tex_size);
 }
 
 void unrealize(GtkWidget *widget) {
@@ -431,6 +434,7 @@ gboolean render(GtkGLArea* area, GdkGLContext* context, RendererControl* con) {
 gboolean export(RendererControl* con, char* path) {
     int width = con->width;
     int height = con->height;
+    
 
     //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
     glViewport(0, 0, width, height);
@@ -475,7 +479,7 @@ gboolean export(RendererControl* con, char* path) {
 
     uint8_t* fb_data = calloc(width*height, sizeof(uint8_t)*3);
 
-    glReadnPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, sizeof(uint8_t)*3*width*height, fb_data);
+    glReadPixels(0, 0, width, height, GL_RGB, GL_UNSIGNED_BYTE, fb_data);
 
     // Flush the contents of the pipeline
     glFlush();

src/rendering/image-renderer.h

@@ -50,6 +50,8 @@ typedef struct RendererControl_ {
     GtkWidget*      ogl_frame;
     GdkPixbuf*      pxb_original;
     void*           image_data;
+    int             original_height;
+    int             original_width;
     int             preview_height;
     int             preview_width;
     int             height;
@@ -73,6 +75,7 @@ typedef struct RendererControl_ {
     GLuint          VAO;
     GLuint          VBO;
     GLuint          EBO;
+    GLint           max_tex_size;
 
     int             processed_fbs_count;