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Diffstat (limited to 'src/imgui_impl_sdl_gl3.cpp')
| -rw-r--r-- | src/imgui_impl_sdl_gl3.cpp | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/src/imgui_impl_sdl_gl3.cpp b/src/imgui_impl_sdl_gl3.cpp new file mode 100644 index 0000000..63d7033 --- /dev/null +++ b/src/imgui_impl_sdl_gl3.cpp @@ -0,0 +1,395 @@ +// ImGui SDL2 binding with OpenGL3 +// In this binding, ImTextureID is used to store an OpenGL 'GLuint' texture identifier. Read the FAQ about ImTextureID in imgui.cpp. + +// You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this. +// If you use this binding you'll need to call 4 functions: ImGui_ImplXXXX_Init(), ImGui_ImplXXXX_NewFrame(), ImGui::Render() and ImGui_ImplXXXX_Shutdown(). +// If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp. +// https://github.com/ocornut/imgui + +#include "imgui.h" +#include "imgui_impl_sdl_gl3.h" + +// SDL,GL3W +#include <SDL.h> +#include <SDL_syswm.h> +#include <GL/glew.h> // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you. + +// Data +static double g_Time = 0.0f; +static bool g_MousePressed[3] = { false, false, false }; +static float g_MouseWheel = 0.0f; +static GLuint g_FontTexture = 0; +static int g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0; +static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; +static int g_AttribLocationPosition = 0, g_AttribLocationUV = 0, g_AttribLocationColor = 0; +static unsigned int g_VboHandle = 0, g_VaoHandle = 0, g_ElementsHandle = 0; + +// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure) +// If text or lines are blurry when integrating ImGui in your engine: +// - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f) +void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data) +{ + // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates) + ImGuiIO& io = ImGui::GetIO(); + int fb_width = (int)(io.DisplaySize.x * io.DisplayFramebufferScale.x); + int fb_height = (int)(io.DisplaySize.y * io.DisplayFramebufferScale.y); + if (fb_width == 0 || fb_height == 0) + return; + draw_data->ScaleClipRects(io.DisplayFramebufferScale); + + // Backup GL state + GLenum last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, (GLint*)&last_active_texture); + glActiveTexture(GL_TEXTURE0); + GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program); + GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); + GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer); + GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer); + GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array); + GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport); + GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); + GLenum last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, (GLint*)&last_blend_src_rgb); + GLenum last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, (GLint*)&last_blend_dst_rgb); + GLenum last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, (GLint*)&last_blend_src_alpha); + GLenum last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, (GLint*)&last_blend_dst_alpha); + GLenum last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, (GLint*)&last_blend_equation_rgb); + GLenum last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, (GLint*)&last_blend_equation_alpha); + GLboolean last_enable_blend = glIsEnabled(GL_BLEND); + GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE); + GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST); + GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST); + + // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled + glEnable(GL_BLEND); + glBlendEquation(GL_FUNC_ADD); + glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); + glDisable(GL_CULL_FACE); + glDisable(GL_DEPTH_TEST); + glEnable(GL_SCISSOR_TEST); + + // Setup viewport, orthographic projection matrix + glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height); + const float ortho_projection[4][4] = + { + { 2.0f/io.DisplaySize.x, 0.0f, 0.0f, 0.0f }, + { 0.0f, 2.0f/-io.DisplaySize.y, 0.0f, 0.0f }, + { 0.0f, 0.0f, -1.0f, 0.0f }, + {-1.0f, 1.0f, 0.0f, 1.0f }, + }; + glUseProgram(g_ShaderHandle); + glUniform1i(g_AttribLocationTex, 0); + glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]); + glBindVertexArray(g_VaoHandle); + + for (int n = 0; n < draw_data->CmdListsCount; n++) + { + const ImDrawList* cmd_list = draw_data->CmdLists[n]; + const ImDrawIdx* idx_buffer_offset = 0; + + glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); + glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW); + + glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle); + glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW); + + for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) + { + const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i]; + if (pcmd->UserCallback) + { + pcmd->UserCallback(cmd_list, pcmd); + } + else + { + glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); + glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y)); + glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset); + } + idx_buffer_offset += pcmd->ElemCount; + } + } + + // Restore modified GL state + glUseProgram(last_program); + glBindTexture(GL_TEXTURE_2D, last_texture); + glActiveTexture(last_active_texture); + glBindVertexArray(last_vertex_array); + glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer); + glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer); + glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha); + glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha); + if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND); + if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE); + if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST); + if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST); + glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]); + glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]); +} + +static const char* ImGui_ImplSdlGL3_GetClipboardText(void*) +{ + return SDL_GetClipboardText(); +} + +static void ImGui_ImplSdlGL3_SetClipboardText(void*, const char* text) +{ + SDL_SetClipboardText(text); +} + +bool ImGui_ImplSdlGL3_ProcessEvent(SDL_Event* event) +{ + ImGuiIO& io = ImGui::GetIO(); + switch (event->type) + { + case SDL_MOUSEWHEEL: + { + if (event->wheel.y > 0) + g_MouseWheel = 1; + if (event->wheel.y < 0) + g_MouseWheel = -1; + return true; + } + case SDL_MOUSEBUTTONDOWN: + { + if (event->button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true; + if (event->button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true; + if (event->button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true; + return true; + } + case SDL_TEXTINPUT: + { + io.AddInputCharactersUTF8(event->text.text); + return true; + } + case SDL_KEYDOWN: + case SDL_KEYUP: + { + int key = event->key.keysym.sym & ~SDLK_SCANCODE_MASK; + io.KeysDown[key] = (event->type == SDL_KEYDOWN); + io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0); + io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0); + io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0); + io.KeySuper = ((SDL_GetModState() & KMOD_GUI) != 0); + return true; + } + } + return false; +} + +void ImGui_ImplSdlGL3_CreateFontsTexture() +{ + // Build texture atlas + ImGuiIO& io = ImGui::GetIO(); + unsigned char* pixels; + int width, height; + io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bits for OpenGL3 demo because it is more likely to be compatible with user's existing shader. + + // Upload texture to graphics system + GLint last_texture; + glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); + glGenTextures(1, &g_FontTexture); + glBindTexture(GL_TEXTURE_2D, g_FontTexture); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); + glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); + glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); + glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels); + + // Store our identifier + io.Fonts->TexID = (void *)(intptr_t)g_FontTexture; + + // Restore state + glBindTexture(GL_TEXTURE_2D, last_texture); +} + +bool ImGui_ImplSdlGL3_CreateDeviceObjects() +{ + // Backup GL state + GLint last_texture, last_array_buffer, last_vertex_array; + glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); + glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer); + glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array); + + const GLchar *vertex_shader = + "#version 330\n" + "uniform mat4 ProjMtx;\n" + "in vec2 Position;\n" + "in vec2 UV;\n" + "in vec4 Color;\n" + "out vec2 Frag_UV;\n" + "out vec4 Frag_Color;\n" + "void main()\n" + "{\n" + " Frag_UV = UV;\n" + " Frag_Color = Color;\n" + " gl_Position = ProjMtx * vec4(Position.xy,0,1);\n" + "}\n"; + + const GLchar* fragment_shader = + "#version 330\n" + "uniform sampler2D Texture;\n" + "in vec2 Frag_UV;\n" + "in vec4 Frag_Color;\n" + "out vec4 Out_Color;\n" + "void main()\n" + "{\n" + " Out_Color = Frag_Color * texture( Texture, Frag_UV.st);\n" + "}\n"; + + g_ShaderHandle = glCreateProgram(); + g_VertHandle = glCreateShader(GL_VERTEX_SHADER); + g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER); + glShaderSource(g_VertHandle, 1, &vertex_shader, 0); + glShaderSource(g_FragHandle, 1, &fragment_shader, 0); + glCompileShader(g_VertHandle); + glCompileShader(g_FragHandle); + glAttachShader(g_ShaderHandle, g_VertHandle); + glAttachShader(g_ShaderHandle, g_FragHandle); + glLinkProgram(g_ShaderHandle); + + g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture"); + g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx"); + g_AttribLocationPosition = glGetAttribLocation(g_ShaderHandle, "Position"); + g_AttribLocationUV = glGetAttribLocation(g_ShaderHandle, "UV"); + g_AttribLocationColor = glGetAttribLocation(g_ShaderHandle, "Color"); + + glGenBuffers(1, &g_VboHandle); + glGenBuffers(1, &g_ElementsHandle); + + glGenVertexArrays(1, &g_VaoHandle); + glBindVertexArray(g_VaoHandle); + glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); + glEnableVertexAttribArray(g_AttribLocationPosition); + glEnableVertexAttribArray(g_AttribLocationUV); + glEnableVertexAttribArray(g_AttribLocationColor); + +#define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT)) + glVertexAttribPointer(g_AttribLocationPosition, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, pos)); + glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, uv)); + glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, col)); +#undef OFFSETOF + + ImGui_ImplSdlGL3_CreateFontsTexture(); + + // Restore modified GL state + glBindTexture(GL_TEXTURE_2D, last_texture); + glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer); + glBindVertexArray(last_vertex_array); + + return true; +} + +void ImGui_ImplSdlGL3_InvalidateDeviceObjects() +{ + if (g_VaoHandle) glDeleteVertexArrays(1, &g_VaoHandle); + if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle); + if (g_ElementsHandle) glDeleteBuffers(1, &g_ElementsHandle); + g_VaoHandle = g_VboHandle = g_ElementsHandle = 0; + + if (g_ShaderHandle && g_VertHandle) glDetachShader(g_ShaderHandle, g_VertHandle); + if (g_VertHandle) glDeleteShader(g_VertHandle); + g_VertHandle = 0; + + if (g_ShaderHandle && g_FragHandle) glDetachShader(g_ShaderHandle, g_FragHandle); + if (g_FragHandle) glDeleteShader(g_FragHandle); + g_FragHandle = 0; + + if (g_ShaderHandle) glDeleteProgram(g_ShaderHandle); + g_ShaderHandle = 0; + + if (g_FontTexture) + { + glDeleteTextures(1, &g_FontTexture); + ImGui::GetIO().Fonts->TexID = 0; + g_FontTexture = 0; + } +} + +bool ImGui_ImplSdlGL3_Init(SDL_Window* window) +{ + ImGuiIO& io = ImGui::GetIO(); + io.KeyMap[ImGuiKey_Tab] = SDLK_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array. + io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT; + io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT; + io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP; + io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN; + io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP; + io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN; + io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME; + io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END; + io.KeyMap[ImGuiKey_Delete] = SDLK_DELETE; + io.KeyMap[ImGuiKey_Backspace] = SDLK_BACKSPACE; + io.KeyMap[ImGuiKey_Enter] = SDLK_RETURN; + io.KeyMap[ImGuiKey_Escape] = SDLK_ESCAPE; + io.KeyMap[ImGuiKey_A] = SDLK_a; + io.KeyMap[ImGuiKey_C] = SDLK_c; + io.KeyMap[ImGuiKey_V] = SDLK_v; + io.KeyMap[ImGuiKey_X] = SDLK_x; + io.KeyMap[ImGuiKey_Y] = SDLK_y; + io.KeyMap[ImGuiKey_Z] = SDLK_z; + + io.RenderDrawListsFn = ImGui_ImplSdlGL3_RenderDrawLists; // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer. + io.SetClipboardTextFn = ImGui_ImplSdlGL3_SetClipboardText; + io.GetClipboardTextFn = ImGui_ImplSdlGL3_GetClipboardText; + io.ClipboardUserData = NULL; + +#ifdef _WIN32 + SDL_SysWMinfo wmInfo; + SDL_VERSION(&wmInfo.version); + SDL_GetWindowWMInfo(window, &wmInfo); + io.ImeWindowHandle = wmInfo.info.win.window; +#else + (void)window; +#endif + + return true; +} + +void ImGui_ImplSdlGL3_Shutdown() +{ + ImGui_ImplSdlGL3_InvalidateDeviceObjects(); + ImGui::Shutdown(); +} + +void ImGui_ImplSdlGL3_NewFrame(SDL_Window* window) +{ + if (!g_FontTexture) + ImGui_ImplSdlGL3_CreateDeviceObjects(); + + ImGuiIO& io = ImGui::GetIO(); + + // Setup display size (every frame to accommodate for window resizing) + int w, h; + int display_w, display_h; + SDL_GetWindowSize(window, &w, &h); + SDL_GL_GetDrawableSize(window, &display_w, &display_h); + io.DisplaySize = ImVec2((float)w, (float)h); + io.DisplayFramebufferScale = ImVec2(w > 0 ? ((float)display_w / w) : 0, h > 0 ? ((float)display_h / h) : 0); + + // Setup time step + Uint32 time = SDL_GetTicks(); + double current_time = time / 1000.0; + io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f / 60.0f); + g_Time = current_time; + + // Setup inputs + // (we already got mouse wheel, keyboard keys & characters from SDL_PollEvent()) + int mx, my; + Uint32 mouseMask = SDL_GetMouseState(&mx, &my); + if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS) + io.MousePos = ImVec2((float)mx, (float)my); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.) + else + io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX); + + io.MouseDown[0] = g_MousePressed[0] || (mouseMask & SDL_BUTTON(SDL_BUTTON_LEFT)) != 0; // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame. + io.MouseDown[1] = g_MousePressed[1] || (mouseMask & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0; + io.MouseDown[2] = g_MousePressed[2] || (mouseMask & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0; + g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false; + + io.MouseWheel = g_MouseWheel; + g_MouseWheel = 0.0f; + + // Hide OS mouse cursor if ImGui is drawing it + SDL_ShowCursor(io.MouseDrawCursor ? 0 : 1); + + // Start the frame + ImGui::NewFrame(); +} |