Add example to use libRmlUi with SDL2 SDL_Renderer / SDL_RenderGeomet…

…ry (#252) * Add example to use libRmlUi with SDL2 SDL_Renderer / SDL_RenderGeometry() * - remove un-needed ifdef opengl. - change window title
mikke89 · Dec 28, 2021 · 8577a0b · 8577a0b
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diff --git a/Samples/basic/sdl2_sdlrenderer/src/RenderInterfaceSDL2.cpp b/Samples/basic/sdl2_sdlrenderer/src/RenderInterfaceSDL2.cpp
@@ -0,0 +1,171 @@
+/*
+ * This source file is part of RmlUi, the HTML/CSS Interface Middleware
+ *
+ * For the latest information, see http://github.com/mikke89/RmlUi
+ *
+ * Copyright (c) 2008-2010 Nuno Silva
+ * Copyright (c) 2019 The RmlUi Team, and contributors
+ *
+ * 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.
+ *
+ */
+
+#include <RmlUi/Core.h>
+#include <SDL_image.h>
+
+#include "RenderInterfaceSDL2.h"
+
+RmlUiSDL2Renderer::RmlUiSDL2Renderer(SDL_Renderer* renderer, SDL_Window* screen)
+{
+    mRenderer = renderer;
+    mScreen = screen;
+
+    SDL_GetRendererOutputSize(renderer, &mRenderer_w, &mRenderer_h);
+
+    mRectScisor.x = 0;
+    mRectScisor.y = 0;
+    mRectScisor.w = mRenderer_w;
+    mRectScisor.h = mRenderer_h;
+}
+
+// Called by RmlUi when it wants to render geometry that it does not wish to optimise.
+void RmlUiSDL2Renderer::RenderGeometry(Rml::Vertex* vertices, int num_vertices, int* indices, int num_indices, const Rml::TextureHandle texture, const Rml::Vector2f& translation)
+{
+    SDL_Texture *sdl_texture = (SDL_Texture *) texture;
+
+    SDL_Rect r;
+    r.x = translation.x;
+    r.y = translation.y;
+    r.w = mRenderer_w - r.x;
+    r.h = mRenderer_h - r.y;
+
+    SDL_RenderSetViewport(mRenderer, &r);
+
+    if (sdl_texture) {
+        SDL_SetTextureBlendMode(sdl_texture, SDL_BLENDMODE_BLEND);
+    }
+
+    int sz = sizeof(vertices[0]);
+    int off1 = offsetof(Rml::Vertex, position);
+    int off2 = offsetof(Rml::Vertex, colour);
+    int off3 = offsetof(Rml::Vertex, tex_coord);
+    SDL_RenderGeometryRaw(mRenderer, sdl_texture, 
+            (float *)((Uint8 *) vertices + off1), sz,
+            (int *)((Uint8 *) vertices + off2), sz,
+            (float *)((Uint8 *) vertices + off3), sz,
+            num_vertices, indices, num_indices, 4);
+
+}
+
+// Called by RmlUi when it wants to enable or disable scissoring to clip content.		
+void RmlUiSDL2Renderer::EnableScissorRegion(bool enable)
+{
+    if (enable) {
+        SDL_RenderSetClipRect(mRenderer, &mRectScisor);
+    } else {
+        SDL_RenderSetClipRect(mRenderer, NULL);
+    }
+}
+
+// Called by RmlUi when it wants to change the scissor region.		
+void RmlUiSDL2Renderer::SetScissorRegion(int x, int y, int width, int height)
+{
+    int w_width, w_height;
+    SDL_GetWindowSize(mScreen, &w_width, &w_height);
+    mRectScisor.x = x;
+    mRectScisor.y = w_height - (y + height);
+    mRectScisor.w = width;
+    mRectScisor.h = height;
+}
+
+// Called by RmlUi when a texture is required by the library.		
+bool RmlUiSDL2Renderer::LoadTexture(Rml::TextureHandle& texture_handle, Rml::Vector2i& texture_dimensions, const Rml::String& source)
+{
+
+    Rml::FileInterface* file_interface = Rml::GetFileInterface();
+    Rml::FileHandle file_handle = file_interface->Open(source);
+    if (!file_handle)
+        return false;
+
+    file_interface->Seek(file_handle, 0, SEEK_END);
+    size_t buffer_size = file_interface->Tell(file_handle);
+    file_interface->Seek(file_handle, 0, SEEK_SET);
+
+    char* buffer = new char[buffer_size];
+    file_interface->Read(buffer, buffer_size, file_handle);
+    file_interface->Close(file_handle);
+
+    size_t i;
+    for(i = source.length() - 1; i > 0; i--)
+    {
+        if(source[i] == '.')
+            break;
+    }
+
+    Rml::String extension = source.substr(i+1, source.length()-i);
+
+    SDL_Surface* surface = IMG_LoadTyped_RW(SDL_RWFromMem(buffer, int(buffer_size)), 1, extension.c_str());
+
+    if (surface) {
+        SDL_Texture *texture = SDL_CreateTextureFromSurface(mRenderer, surface);
+
+        if (texture) {
+            texture_handle = (Rml::TextureHandle) texture;
+            texture_dimensions = Rml::Vector2i(surface->w, surface->h);
+            SDL_FreeSurface(surface);
+        }
+        else
+        {
+            return false;
+        }
+
+        return true;
+    }
+
+    return false;
+}
+
+// Called by RmlUi when a texture is required to be built from an internally-generated sequence of pixels.
+bool RmlUiSDL2Renderer::GenerateTexture(Rml::TextureHandle& texture_handle, const Rml::byte* source, const Rml::Vector2i& source_dimensions)
+{
+    #if SDL_BYTEORDER == SDL_BIG_ENDIAN
+        Uint32 rmask = 0xff000000;
+        Uint32 gmask = 0x00ff0000;
+        Uint32 bmask = 0x0000ff00;
+        Uint32 amask = 0x000000ff;
+    #else
+        Uint32 rmask = 0x000000ff;
+        Uint32 gmask = 0x0000ff00;
+        Uint32 bmask = 0x00ff0000;
+        Uint32 amask = 0xff000000;
+    #endif
+
+    SDL_Surface *surface = SDL_CreateRGBSurfaceFrom ((void*) source, source_dimensions.x, source_dimensions.y, 32, source_dimensions.x*4, rmask, gmask, bmask, amask);
+    SDL_Texture *texture = SDL_CreateTextureFromSurface(mRenderer, surface);
+    SDL_SetTextureBlendMode(texture, SDL_BLENDMODE_BLEND);
+    SDL_FreeSurface(surface);
+    texture_handle = (Rml::TextureHandle) texture;
+    return true;
+}
+
+// Called by RmlUi when a loaded texture is no longer required.		
+void RmlUiSDL2Renderer::ReleaseTexture(Rml::TextureHandle texture_handle)
+{
+    SDL_DestroyTexture((SDL_Texture*) texture_handle);
+}
diff --git a/Samples/basic/sdl2_sdlrenderer/src/RenderInterfaceSDL2.h b/Samples/basic/sdl2_sdlrenderer/src/RenderInterfaceSDL2.h
@@ -0,0 +1,68 @@
+/*
+ * This source file is part of RmlUi, the HTML/CSS Interface Middleware
+ *
+ * For the latest information, see http://github.com/mikke89/RmlUi
+ *
+ * Copyright (c) 2008-2010 Nuno Silva
+ * Copyright (c) 2019 The RmlUi Team, and contributors
+ *
+ * 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 RENDERINTERFACESDL2_H
+#define RENDERINTERFACESDL2_H
+
+#include <RmlUi/Core/RenderInterface.h>
+
+#include <SDL.h>
+
+#if !(SDL_VIDEO_RENDER_OGL)
+    #error "Only the opengl sdl backend is supported."
+#endif
+
+
+class RmlUiSDL2Renderer : public Rml::RenderInterface
+{
+public:
+	RmlUiSDL2Renderer(SDL_Renderer* renderer, SDL_Window* screen);
+
+	/// Called by RmlUi when it wants to render geometry that it does not wish to optimise.
+	void RenderGeometry(Rml::Vertex* vertices, int num_vertices, int* indices, int num_indices, Rml::TextureHandle texture, const Rml::Vector2f& translation) override;
+
+	/// Called by RmlUi when it wants to enable or disable scissoring to clip content.
+	void EnableScissorRegion(bool enable) override;
+	/// Called by RmlUi when it wants to change the scissor region.
+	void SetScissorRegion(int x, int y, int width, int height) override;
+
+	/// Called by RmlUi when a texture is required by the library.
+	bool LoadTexture(Rml::TextureHandle& texture_handle, Rml::Vector2i& texture_dimensions, const Rml::String& source) override;
+	/// Called by RmlUi when a texture is required to be built from an internally-generated sequence of pixels.
+	bool GenerateTexture(Rml::TextureHandle& texture_handle, const Rml::byte* source, const Rml::Vector2i& source_dimensions) override;
+	/// Called by RmlUi when a loaded texture is no longer required.
+	void ReleaseTexture(Rml::TextureHandle texture_handle) override;
+
+private:
+    SDL_Renderer* mRenderer;
+    int mRenderer_w;
+    int mRenderer_h;
+    SDL_Window* mScreen;
+    SDL_Rect mRectScisor;
+};
+
+#endif