add GLES 2 renderer for 2D

This commit adds a new rendering backend, GLES2, and adds a
project setting to enable it.

Currently this backend can only be used on the X11 platform,
but integrating into other platforms is planned.

1 files changed, 129 insertions, 0 deletions

diff --git a/drivers/gles2/rasterizer_canvas_gles2.h b/drivers/gles2/rasterizer_canvas_gles2.h
new file mode 100644
index 0000000000..06dcc57df4
--- /dev/null
+++ b/drivers/gles2/rasterizer_canvas_gles2.h
@@ -0,0 +1,129 @@
+/*************************************************************************/
+/*  rasterizer_canvas_gles2.h                                            */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md)    */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+#ifndef RASTERIZERCANVASGLES2_H
+#define RASTERIZERCANVASGLES2_H
+
+#include "rasterizer_storage_gles2.h"
+#include "servers/visual/rasterizer.h"
+
+#include "shaders/canvas.glsl.gen.h"
+
+// #include "shaders/canvas_shadow.glsl.gen.h"
+
+class RasterizerSceneGLES2;
+
+class RasterizerCanvasGLES2 : public RasterizerCanvas {
+public:
+	struct Uniforms {
+		Transform projection_matrix;
+
+		Transform2D modelview_matrix;
+		Transform2D extra_matrix;
+
+		Color final_modulate;
+
+		float time;
+	};
+
+	struct Data {
+
+		GLuint canvas_quad_vertices;
+		GLuint polygon_buffer;
+		GLuint polygon_index_buffer;
+
+		uint32_t polygon_buffer_size;
+
+		GLuint ninepatch_vertices;
+		GLuint ninepatch_elements;
+
+	} data;
+
+	struct State {
+		Uniforms uniforms;
+		bool canvas_texscreen_used;
+		CanvasShaderGLES2 canvas_shader;
+		// CanvasShadowShaderGLES3 canvas_shadow_shader;
+
+		bool using_texture_rect;
+		bool using_ninepatch;
+
+		RID current_tex;
+		RID current_normal;
+		RasterizerStorageGLES2::Texture *current_tex_ptr;
+
+		Transform vp;
+
+	} state;
+
+	typedef void Texture;
+
+	RasterizerSceneGLES2 *scene_render;
+
+	RasterizerStorageGLES2 *storage;
+
+	virtual RID light_internal_create();
+	virtual void light_internal_update(RID p_rid, Light *p_light);
+	virtual void light_internal_free(RID p_rid);
+
+	void _set_uniforms();
+
+	virtual void canvas_begin();
+	virtual void canvas_end();
+
+	_FORCE_INLINE_ void _set_texture_rect_mode(bool p_enable, bool p_ninepatch = false);
+
+	_FORCE_INLINE_ void _draw_gui_primitive(int p_points, const Vector2 *p_vertices, const Color *p_colors, const Vector2 *p_uvs);
+	_FORCE_INLINE_ void _draw_polygon(const int *p_indices, int p_index_count, int p_vertex_count, const Vector2 *p_vertices, const Vector2 *p_uvs, const Color *p_colors, bool p_singlecolor);
+	_FORCE_INLINE_ void _draw_generic(GLuint p_primitive, int p_vertex_count, const Vector2 *p_vertices, const Vector2 *p_uvs, const Color *p_colors, bool p_singlecolor);
+
+	_FORCE_INLINE_ void _canvas_item_render_commands(Item *p_item, Item *current_clip, bool &reclip);
+	_FORCE_INLINE_ void _copy_texscreen(const Rect2 &p_rect);
+
+	virtual void canvas_render_items(Item *p_item_list, int p_z, const Color &p_modulate, Light *p_light, const Transform2D &p_base_transform);
+	virtual void canvas_debug_viewport_shadows(Light *p_lights_with_shadow);
+
+	virtual void canvas_light_shadow_buffer_update(RID p_buffer, const Transform2D &p_light_xform, int p_light_mask, float p_near, float p_far, LightOccluderInstance *p_occluders, CameraMatrix *p_xform_cache);
+
+	virtual void reset_canvas();
+
+	RasterizerStorageGLES2::Texture *_bind_canvas_texture(const RID &p_texture, const RID &p_normal_map);
+
+	void _bind_quad_buffer();
+	void draw_generic_textured_rect(const Rect2 &p_rect, const Rect2 &p_src);
+
+	void initialize();
+	void finalize();
+
+	virtual void draw_window_margins(int *black_margin, RID *black_image);
+
+	RasterizerCanvasGLES2();
+};
+
+#endif // RASTERIZERCANVASGLES2_H