[GTK3] Implement OpenGL renderer prototype

Makefile

@@ -108,8 +108,11 @@ ifneq ($(findstring gtk3,$(MAKECMDGOALS)),)
 $(error The gtk3 target requires pkg-config)
 endif
 else
-GTK3_CFLAGS  := $(shell $(PKG_CONFIG) --cflags gtk+-3.0) -DGTK_DISABLE_DEPRECATED=1 -DG_DISABLE_DEPRECATED=1
+GTK3_CFLAGS  := $(shell $(PKG_CONFIG) --cflags gio-2.0 gtk+-3.0 epoxy) -DGTK_DISABLE_DEPRECATED=1 -DG_DISABLE_DEPRECATED=1 -DRESOURCE_PREFIX=\"/io/github/sameboy/\" -DAPP_ID=\"io.github.sameboy\"
-GTK3_LDFLAGS := $(shell $(PKG_CONFIG) --libs gtk+-3.0)
+GTK3_LDFLAGS := $(shell $(PKG_CONFIG) --libs gio-2.0 gtk+-3.0 epoxy)
+
+# TODO: REMOVE DISABLE UNUSED WARNINGS
+GTK3_CFLAGS += -Wno-unused
 endif
 
 ifeq ($(PLATFORM),windows32)

gtk3/main.c

@@ -1,27 +1,87 @@
 #include <gtk/gtk.h>
+#include <epoxy/gl.h>
 #include <signal.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <string.h>
 #include <Core/gb.h>
+#include "shader.h"
 
 #define str(x) #x
 #define xstr(x) str(x)
 
-#define RESOURCE_PREFIX "/io/github/sameboy/"
-#define APP_ID "io.github.sameboy"
-
 GtkBuilder *builder;
 GtkWindow *main_window;
 GtkGLArea *gl_area;
+shader_t shader;
 
 GB_gameboy_t gb;
+static bool paused = false;
+static uint32_t pixel_buffer_1[256 * 224], pixel_buffer_2[256 * 224];
+static uint32_t *active_pixel_buffer = pixel_buffer_1, *previous_pixel_buffer = pixel_buffer_2;
+static bool underclock_down = false, rewind_down = false, do_rewind = false, rewind_paused = false, turbo_down = false;
+static double clock_mutliplier = 1.0;
+
+static typeof(free) *free_function = NULL;
+static char *battery_save_path_ptr;
+
 
 typedef struct UserData {
 	bool fullscreen;
 	GFile *file;
 } UserData;
 
+typedef struct{
+	int16_t x, y;
+	uint16_t w, h;
+} Rect;
+
+static void run(UserData *user_data);
+
+static Rect rect;
+
+void render_texture(void *pixels,  void *previous) {
+	static void *_pixels = NULL;
+	if (pixels) {
+		_pixels = pixels;
+	}
+
+	glClearColor(0, 0, 0, 1);
+	glClear(GL_COLOR_BUFFER_BIT);
+	
+	render_bitmap_with_shader(&shader, _pixels, previous, GB_get_screen_width(&gb), GB_get_screen_height(&gb), rect.x, rect.y, rect.w, rect.h);
+	gtk_widget_queue_draw(GTK_WIDGET(gl_area));
+}
+
+void update_viewport(void) {
+    int win_width = gtk_widget_get_allocated_width(GTK_WIDGET(gl_area));
+    int win_height = gtk_widget_get_allocated_height(GTK_WIDGET(gl_area));
+    
+    double x_factor = win_width / (double) GB_get_screen_width(&gb);
+    double y_factor = win_height / (double) GB_get_screen_height(&gb);
+    
+    if (true /*configuration.scaling_mode == GB_SDL_SCALING_INTEGER_FACTOR*/) {
+        x_factor = (int)(x_factor);
+        y_factor = (int)(y_factor);
+    }
+    
+    /*if (configuration.scaling_mode != GB_SDL_SCALING_ENTIRE_WINDOW) {
+        if (x_factor > y_factor) {
+            x_factor = y_factor;
+        }
+        else {
+            y_factor = x_factor;
+        }
+    }*/
+    
+    unsigned new_width = x_factor * GB_get_screen_width(&gb);
+    unsigned new_height = y_factor * GB_get_screen_height(&gb);
+    
+    rect = (Rect){(win_width  - new_width) / 2, (win_height - new_height) / 2, new_width, new_height};
+    
+    glViewport(rect.x, rect.y, rect.w, rect.h);
+}
+
 // Determines if a ComboBox entry should be converted into a separator.
 // Each element with a text value of `<separator>` will be converted into a separator element.
 static gboolean is_separator(GtkTreeModel *model, GtkTreeIter *iter, gpointer data) {
@@ -108,6 +168,43 @@ G_MODULE_EXPORT void on_boot_rom_location_changed(GtkWidget *w, gpointer user_da
 	g_print("Active: %s", gtk_combo_box_get_active_id(box));
 }
 
+G_MODULE_EXPORT void gl_draw(GtkWidget *window) {
+	render_texture(active_pixel_buffer, NULL);
+}
+
+G_MODULE_EXPORT void gl_init(GtkWidget *window) {
+	const char *renderer;
+
+	GList *children = gtk_container_get_children(GTK_CONTAINER(window));
+
+	while (children) {
+		if (GTK_IS_GL_AREA(children->data)) {
+			gl_area = GTK_GL_AREA(children->data);
+			break;
+		}
+
+		children = children->next;
+	}
+	g_list_free(children);
+
+	if (gl_area == NULL) {
+		g_printerr("Unable to find GtkGLArea in window\n");
+		return;
+	}
+
+	gtk_gl_area_make_current(gl_area);
+	if (gtk_gl_area_get_error(gl_area) != NULL) {
+		return;
+	}
+
+	renderer = (char *) glGetString(GL_RENDERER);
+	g_print("GtkGLArea on %s\n", renderer ? renderer : "Unknown");
+
+	if (!init_shader_with_name(&shader, /*configuration.filter*/ "OmniScale")) {
+		init_shader_with_name(&shader, "NearestNeighbor");
+	}
+}
+
 // This functions gets called immediately after registration of the GApplication
 static void startup(GApplication *app, gpointer user_data_gptr) {
 	// UserData *user_data = user_data_gptr;
@@ -180,10 +277,6 @@ static void startup(GApplication *app, gpointer user_data_gptr) {
 	gtk_about_dialog_set_logo(about_dialog, g_list_nth_data(icon_list, 3)); // reuse the 64x64 icon
 	gtk_about_dialog_set_version(about_dialog, "v" xstr(VERSION));
 	g_list_free(icon_list);
-
-	GList *children = gtk_container_get_children(GTK_CONTAINER(main_window));
-	gl_area = GTK_GL_AREA(g_list_first(children));
-	g_list_free(children);
 }
 
 // This function gets called when the GApplication gets activated, i.e. it is ready to show widgets.
@@ -197,6 +290,9 @@ static void activate(GApplication *app, gpointer user_data_gptr) {
 	g_signal_connect(main_window, "destroy", G_CALLBACK(gtk_main_quit), NULL);
 	gtk_application_add_window(GTK_APPLICATION(app), main_window);
 	gtk_widget_show_all(GTK_WIDGET(main_window));
+
+	update_viewport();
+	run(user_data);
 }
 
 // This function gets called when there are files to open.
@@ -233,7 +329,77 @@ static gint handle_local_options(GApplication *app, GVariantDict *options, gpoin
 	return -1;
 }
 
-int main (int argc, char *argv[]) {
+static uint32_t rgb_encode(GB_gameboy_t *gb, uint8_t r, uint8_t g, uint8_t b) {
+	uint32_t color = 0xFF000000 | (b << 16) | (g << 8) | r; // abgr
+	return color;
+}
+
+static void vblank(GB_gameboy_t *gb) {
+	// render_texture(active_pixel_buffer, NULL);
+
+	while (gtk_events_pending()) {
+		gtk_main_iteration();
+	}
+}
+
+static void run(UserData *user_data) {
+	GB_model_t model = GB_MODEL_CGB_E;
+
+	if (GB_is_inited(&gb)) {
+		GB_switch_model_and_reset(&gb, model);
+	}
+	else {
+		GB_init(&gb, model);
+
+		GB_set_vblank_callback(&gb, (GB_vblank_callback_t) vblank);
+		GB_set_pixels_output(&gb, active_pixel_buffer);
+		GB_set_rgb_encode_callback(&gb, rgb_encode);
+		// GB_set_sample_rate(&gb, have_aspec.freq);
+		// GB_set_color_correction_mode(&gb, configuration.color_correction_mode);
+		// GB_set_highpass_filter_mode(&gb, configuration.highpass_mode);
+		// GB_set_rewind_length(&gb, configuration.rewind_length);
+		// GB_set_update_input_hint_callback(&gb, handle_events);
+		// GB_apu_set_sample_callback(&gb, gb_audio_callback);
+	}
+
+	GError *gerror;
+	GBytes *boot_rom_f;
+	const guchar *boot_rom_data;
+	gsize boot_rom_size;
+	
+	boot_rom_f = g_resources_lookup_data(RESOURCE_PREFIX "bootroms/cgb_boot.bin", G_RESOURCE_LOOKUP_FLAGS_NONE, &gerror);
+	boot_rom_data = g_bytes_get_data(boot_rom_f, &boot_rom_size);
+
+	GB_load_boot_rom_from_buffer(&gb, boot_rom_data, boot_rom_size);
+	
+	if (user_data->file != NULL) {
+		GB_load_rom(&gb, g_file_get_path(user_data->file));
+	}
+
+	/* Run emulation */
+	while (true) {
+		if (paused || rewind_paused) {
+			while (gtk_events_pending()) {
+				gtk_main_iteration();
+			}
+		}
+		else {
+			if (do_rewind) {
+				GB_rewind_pop(&gb);
+				if (turbo_down) {
+					GB_rewind_pop(&gb);
+				}
+				if (!GB_rewind_pop(&gb)) {
+					rewind_paused = true;
+				}
+				do_rewind = false;
+			}
+			GB_run(&gb);
+		}
+	}
+}
+
+int main(int argc, char *argv[]) {
 	// Create our GApplication and tell GTK that we are able to handle files
 	GtkApplication *app = gtk_application_new(APP_ID, G_APPLICATION_HANDLES_OPEN);
 

gtk3/resources/ui/window.ui

@@ -979,6 +979,9 @@ Maximilian Mader https://github.com/max-m</property>
         <property name="visible">True</property>
         <property name="app_paintable">True</property>
         <property name="can_focus">False</property>
+        <signal name="realize" handler="gl_init" object="main_no_titlebar" swapped="yes"/>
+        <signal name="render" handler="gl_draw" object="main_no_titlebar" swapped="yes"/>
+        <signal name="unrealize" handler="gl_finish" object="main_no_titlebar" swapped="yes"/>
       </object>
     </child>
   </object>
@@ -1017,6 +1020,9 @@ Maximilian Mader https://github.com/max-m</property>
         <property name="visible">True</property>
         <property name="app_paintable">True</property>
         <property name="can_focus">False</property>
+        <signal name="realize" handler="gl_init" object="main_with_titlebar" swapped="yes"/>
+        <signal name="render" handler="gl_draw" object="main_with_titlebar" swapped="yes"/>
+        <signal name="unrealize" handler="gl_finish" object="main_with_titlebar" swapped="yes"/>
       </object>
     </child>
   </object>

gtk3/shader.c

@@ -0,0 +1,206 @@
+#include <glib.h>
+#include <gio/gio.h>
+#include "shader.h"
+
+static const char *vertex_shader = "\n\
+#version 150 \n\
+in vec4 aPosition;\n\
+void main(void) {\n\
+gl_Position = aPosition;\n\
+}\n\
+";
+
+static GLuint create_shader(const char *source, GLenum type)
+{
+    // Create the shader object
+    GLuint shader = glCreateShader(type);
+    // Load the shader source
+    glShaderSource(shader, 1, &source, 0);
+    // Compile the shader
+    glCompileShader(shader);
+    // Check for errors
+    GLint status = 0;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &status);
+    if (status == GL_FALSE) {
+        GLchar messages[1024];
+        glGetShaderInfoLog(shader, sizeof(messages), 0, &messages[0]);
+        g_printerr("GLSL Shader Error: %s", messages);
+    }
+    return shader;
+}
+
+static GLuint create_program(const char *vsh, const char *fsh)
+{
+    // Build shaders
+    GLuint vertex_shader = create_shader(vsh, GL_VERTEX_SHADER);
+    GLuint fragment_shader = create_shader(fsh, GL_FRAGMENT_SHADER);
+    
+    // Create program
+    GLuint program = glCreateProgram();
+    
+    // Attach shaders
+    glAttachShader(program, vertex_shader);
+    glAttachShader(program, fragment_shader);
+    
+    // Link program
+    glLinkProgram(program);
+    // Check for errors
+    GLint status;
+    glGetProgramiv(program, GL_LINK_STATUS, &status);
+    
+    if (status == GL_FALSE) {
+        GLchar messages[1024];
+        glGetProgramInfoLog(program, sizeof(messages), 0, &messages[0]);
+        g_printerr("GLSL Program Error: %s", messages);
+    }
+    
+    // Delete shaders
+    glDeleteShader(vertex_shader);
+    glDeleteShader(fragment_shader);
+    
+    return program;
+}
+
+bool init_shader_with_name(shader_t *shader, const char *name)
+{
+    GLint major = 0, minor = 0;
+    glGetIntegerv(GL_MAJOR_VERSION, &major);
+    glGetIntegerv(GL_MINOR_VERSION, &minor);
+    
+    if (major * 0x100 + minor < 0x302) {
+        return false;
+    }
+    
+    GError *error;
+    GBytes *master_shader_f;
+    static const gchar *master_shader_code;
+    static gsize master_shader_code_size;
+
+    static char final_shader_code[0x10801] = {0,};
+    static signed long filter_token_location = 0;
+    
+    if (!master_shader_code_size) {
+        master_shader_f = g_resources_lookup_data(RESOURCE_PREFIX "Shaders/MasterShader.fsh", G_RESOURCE_LOOKUP_FLAGS_NONE, &error);
+        master_shader_code = g_bytes_get_data(master_shader_f, &master_shader_code_size);
+
+        if (!master_shader_f) {
+            g_printerr("Failed to load master shader: %s", error->message);
+            return false;
+        }
+
+        filter_token_location = strstr(master_shader_code, "{filter}") - master_shader_code;
+        if (filter_token_location < 0) {
+            return false;
+        }
+    }
+    
+    char shader_path[1024];
+    g_snprintf(shader_path, sizeof(shader_path), RESOURCE_PREFIX "Shaders/%s.fsh", name);
+    
+    GBytes *shader_f = g_resources_lookup_data(shader_path, G_RESOURCE_LOOKUP_FLAGS_NONE, &error);
+    if (!shader_f) {
+        g_printerr("Failed to load shader \"%s\": %s", shader_path, error->message);
+        return false;
+    }
+
+    gsize shader_code_size;
+    const gchar *shader_code = g_bytes_get_data(shader_f, &shader_code_size);
+    
+    memset(final_shader_code, 0, sizeof(final_shader_code));
+    memcpy(final_shader_code, master_shader_code, filter_token_location);
+    strcpy(final_shader_code + filter_token_location, shader_code);
+    strcat(final_shader_code + filter_token_location,
+           master_shader_code + filter_token_location + sizeof("{filter}") - 1);
+    
+    shader->program = create_program(vertex_shader, final_shader_code);
+    
+    // Attributes
+    shader->position_attribute = glGetAttribLocation(shader->program, "aPosition");
+    // Uniforms
+    shader->resolution_uniform = glGetUniformLocation(shader->program, "output_resolution");
+    shader->origin_uniform = glGetUniformLocation(shader->program, "origin");
+
+    glGenTextures(1, &shader->texture);
+    glBindTexture(GL_TEXTURE_2D, shader->texture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glBindTexture(GL_TEXTURE_2D, 0);
+    shader->texture_uniform = glGetUniformLocation(shader->program, "image");
+    
+    glGenTextures(1, &shader->previous_texture);
+    glBindTexture(GL_TEXTURE_2D, shader->previous_texture);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+    glBindTexture(GL_TEXTURE_2D, 0);
+    shader->previous_texture_uniform = glGetUniformLocation(shader->program, "previous_image");
+    
+    shader->mix_previous_uniform = glGetUniformLocation(shader->program, "mix_previous");
+    
+    // Program
+    
+    glUseProgram(shader->program);
+    
+    GLuint vao;
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+    
+    GLuint vbo;
+    glGenBuffers(1, &vbo);
+    
+    // Attributes
+    
+    static GLfloat const quad[16] = {
+        -1.f, -1.f, 0, 1,
+        -1.f, +1.f, 0, 1,
+        +1.f, -1.f, 0, 1,
+        +1.f, +1.f, 0, 1,
+    };
+    
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(quad), quad, GL_STATIC_DRAW);
+    glEnableVertexAttribArray(shader->position_attribute);
+    glVertexAttribPointer(shader->position_attribute, 4, GL_FLOAT, GL_FALSE, 0, 0);
+    
+    return true;
+}
+
+void render_bitmap_with_shader(shader_t *shader, void *bitmap, void *previous,
+                               unsigned source_width, unsigned source_height,
+                               unsigned x, unsigned y, unsigned w, unsigned h)
+{
+    glUseProgram(shader->program);
+    glUniform2f(shader->origin_uniform, x, y);
+    glUniform2f(shader->resolution_uniform, w, h);
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, shader->texture);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, source_width, source_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, bitmap);
+    glUniform1i(shader->texture_uniform, 0);
+    glUniform1i(shader->mix_previous_uniform, previous != NULL);
+    if (previous) {
+        glActiveTexture(GL_TEXTURE1);
+        glBindTexture(GL_TEXTURE_2D, shader->previous_texture);
+        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, source_width, source_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, previous);
+        glUniform1i(shader->previous_texture_uniform, 1);
+    }
+    glBindFragDataLocation(shader->program, 0, "frag_color");
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+}
+
+void free_shader(shader_t *shader)
+{
+    GLint major = 0, minor = 0;
+    glGetIntegerv(GL_MAJOR_VERSION, &major);
+    glGetIntegerv(GL_MINOR_VERSION, &minor);
+    
+    if (major * 0x100 + minor < 0x302) {
+        return;
+    }
+    
+    glDeleteProgram(shader->program);
+    glDeleteTextures(1, &shader->texture);
+    glDeleteTextures(1, &shader->previous_texture);
+}

gtk3/shader.h

@@ -0,0 +1,25 @@
+#ifndef shader_h
+#define shader_h
+#include <epoxy/gl.h>
+#include <stdbool.h>
+
+typedef struct shader_s {
+    GLuint resolution_uniform;
+    GLuint origin_uniform;
+    GLuint texture_uniform;
+    GLuint previous_texture_uniform;
+    GLuint mix_previous_uniform;
+    
+    GLuint position_attribute;
+    GLuint texture;
+    GLuint previous_texture;
+    GLuint program;
+} shader_t;
+
+bool init_shader_with_name(shader_t *shader, const char *name);
+void render_bitmap_with_shader(shader_t *shader, void *bitmap, void *previous,
+                               unsigned source_width, unsigned source_height,
+                               unsigned x, unsigned y, unsigned w, unsigned h);
+void free_shader(struct shader_s *shader);
+
+#endif /* shader_h */