Add common interface for backends & move context to ImPlotContext

backends/implot_gpu.h

@@ -0,0 +1,154 @@
+// MIT License
+
+// Copyright (c) 2021 Evan Pezent
+
+// 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.
+
+// ImPlot v0.10 WIP
+
+#pragma once
+
+#include "../implot.h"
+
+namespace ImPlot {
+namespace Backend {
+
+/**
+ * @brief Struct to hold backend-related context data
+ *
+ * A backend may store in this struct any data it needs, with no constraints. A
+ * pointer to this struct will be stored inside ImPlot's context and can be
+ * accessed at any time. This pointer will be set to the returned value of @ref
+ * CreateContext(). All resources held by this struct must be freed inside @ref
+ * DestroyContext().
+ */
+struct ContextData;
+
+/**
+ * @brief Create backend context
+ *
+ * Creates and intializes the backend context. The returned pointer will be saved
+ * in ImPlot's context and can be accessed later.
+ */
+IMPLOT_API void* CreateContext();
+
+/**
+ * @brief Destroy backend context
+ *
+ * Destroys and frees any memory or resources needed by the backend. After this
+ * call returns, no more calls to any backend function will be performed.
+ */
+IMPLOT_API void DestroyContext();
+
+/**
+ * @brief Add a colormap
+ *
+ * Adds a colormap to be handled by the backend.
+ *
+ * @param keys   Colors for this colormap, in RGBA format
+ * @param count  Number of colors in this colormap
+ * @param qual   Qualitative: whether the colormap is continuous (`false`) or
+ *               not (`true`)
+ */
+IMPLOT_API void AddColormap(const ImU32* keys, int count, bool qual);
+
+/**
+ * @brief Set heatmap data
+ *
+ * Sets the data of the heatmap with the given plot ID.
+ *
+ * @param plotID  ID of the heatmap to update. This ID is unique, but it is not
+ *                continuous nor always positive.
+ * @param values  Data of the heatmap to be set.`values[0]` corresponds with the
+ *                top-left corner of the data.
+ * @param rows    Number of rows of this heatmap
+ * @param cols    Number of columns of this heatmap
+ */
+IMPLOT_API void SetHeatmapData(int plotID, const ImS8*   values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImU8*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImU8*   values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImS16*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImS16*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImU16*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImU16*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImS32*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImS32*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImU32*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImU32*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const float*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const float*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const double*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const double* values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImS64*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImS64*  values, int rows, int cols);
+
+/** @copydoc SetHeatmapData(int,const ImU64*,int,int) */
+IMPLOT_API void SetHeatmapData(int plotID, const ImU64*  values, int rows, int cols);
+
+/**
+ * @brief Render heatmap
+ *
+ * Renders the heatmap by submitting the appropriate commands to the current
+ * draw list.
+ *
+ * @param plotID      ID of the heatmap to be rendered
+ * @param DrawList    Draw list where to submit the render commands
+ * @param bounds_min  Minimum bounds of the heatmap (without clipping)
+ * @param bounds_max  Maximum bounds of the heatmap (without clipping)
+ * @param scale_min   Minimum value of the heatmap
+ * @param scale_max   Maximum value of the heatmap
+ * @param colormap    Colormap to be used when rendering this heatmap
+ *
+ * @note There might be values greater than `scale_max` or lower than `scale_min`.
+ *       The shader used for rendering should clamp this values appropriately.
+ */
+IMPLOT_API void RenderHeatmap(
+	int plotID, ImDrawList& DrawList, const ImVec2& bounds_min, const ImVec2& bounds_max,
+	float scale_min, float scale_max, ImPlotColormap colormap);
+
+/** @brief Bust plot cache. Called from @ref ImPlot::BustPlotCache() */
+IMPLOT_API void BustPlotCache();
+
+/** @brief Bust item cache. Called from @ref ImPlot::BustItemCache() */
+IMPLOT_API void BustItemCache();
+
+
+#if !defined(IMPLOT_ENABLE_OPENGL3_ACCELERATION)
+
+// Dummy implementation for backend functions
+inline void* CreateContext() { return nullptr; }
+inline void DestroyContext() {}
+
+inline void AddColormap(const ImU32*, int, bool) {}
+
+inline void BustPlotCache() {}
+inline void BustItemCache() {}
+
+#endif
+
+}
+}

backends/implot_opengl3.cpp

@@ -2,6 +2,7 @@
 
 #include "../implot.h"
 #include "../implot_internal.h"
+#include "implot_gpu.h"
 
 #if defined(IMGUI_IMPL_OPENGL_ES2)
 #include <GLES2/gl2.h>
@@ -32,7 +33,7 @@ using namespace gl;
 #endif
 
 namespace ImPlot {
-namespace Backends {
+namespace Backend {
 
 struct HeatmapData
 {
@@ -42,7 +43,7 @@ struct HeatmapData
 	float MaxValue;
 };
 
-struct OpenGLContextData
+struct ContextData
 {
 	GLuint g_ShaderProgram = 0;                 ///< Shader ID for the heatmap shader
 	GLuint g_AttribLocationHeatmapSampler = 0;  ///< Attribute location for the heatmap texture
@@ -62,10 +63,29 @@ struct OpenGLContextData
 	ImVector<ImU32> temp3;
 };
 
-static OpenGLContextData Context;
+void* CreateContext()
+{
+	return new ContextData;
+}
+
+void DestroyContext()
+{
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
+	for(const HeatmapData& data : Context.HeatmapDataList)
+		glDeleteTextures(1, &data.HeatmapTexID);
+
+	for(GLuint texID : Context.ColormapIDs)
+		glDeleteTextures(1, &texID);
+
+	Context.HeatmapDataList.clear();
+	Context.PlotIDs.Clear();
+}
 
 static void CreateShader(const ImDrawList*, const ImDrawCmd*)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	GLuint CurrentShader;
 	glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&CurrentShader);
 
@@ -73,14 +93,12 @@ static void CreateShader(const ImDrawList*, const ImDrawCmd*)
 
 	GLuint g_AttribLocationVtxPos   = (GLuint)glGetAttribLocation(CurrentShader, "Position");
 	GLuint g_AttribLocationVtxUV    = (GLuint)glGetAttribLocation(CurrentShader, "UV");
-	GLuint g_AttribLocationVtxColor = (GLuint)glGetAttribLocation(CurrentShader, "Color");
 
 	const GLchar* VertexShaderCode_t =
 		"#version 330 core\n"
 		"precision mediump float;\n"
 		"layout (location = %d) in vec2 Position;\n"
 		"layout (location = %d) in vec2 UV;\n"
-		"layout (location = %d) in vec4 Color;\n"
 		"\n"
 		"uniform mat4 ProjMtx;\n"
 		"out vec2 Frag_UV;\n"
@@ -110,7 +128,7 @@ static void CreateShader(const ImDrawList*, const ImDrawCmd*)
 		"}\n";
 
 	GLchar* VertexShaderCode = new GLchar[512];
-	snprintf(VertexShaderCode, 512, VertexShaderCode_t, g_AttribLocationVtxPos, g_AttribLocationVtxUV, g_AttribLocationVtxColor);
+	snprintf(VertexShaderCode, 512, VertexShaderCode_t, g_AttribLocationVtxPos, g_AttribLocationVtxUV);
 
 	GLuint g_VertexShader = glCreateShader(GL_VERTEX_SHADER);
 	glShaderSource(g_VertexShader, 1, &VertexShaderCode, nullptr);
@@ -145,6 +163,8 @@ static void CreateShader(const ImDrawList*, const ImDrawCmd*)
 
 static void RenderCallback(const ImDrawList*, const ImDrawCmd* cmd)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	int plotID = (int)(intptr_t)cmd->UserCallbackData;
 	int plotIdx = Context.PlotIDs.GetInt(plotID, -1);
 	HeatmapData& data = Context.HeatmapDataList[plotIdx];
@@ -175,6 +195,8 @@ static void UnbindTexture(const ImDrawList*, const ImDrawCmd*)
 
 static void SetTextureData(int plotID, const void* data, GLsizei rows, GLsizei cols, GLenum type)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	int idx = Context.PlotIDs.GetInt(plotID, -1);
 	GLuint texID = Context.HeatmapDataList[idx].HeatmapTexID;
 
@@ -183,7 +205,7 @@ static void SetTextureData(int plotID, const void* data, GLsizei rows, GLsizei c
 	glTexImage2D(GL_TEXTURE_2D, 0, GL_R32F, cols, rows, 0, GL_RED, type, data);
 }
 
-void OpenGL3_AddColormap(const ImU32* keys, int count, bool qual)
+void AddColormap(const ImU32* keys, int count, bool qual)
 {
 	GLuint texID;
 	glGenTextures(1, &texID);
@@ -195,6 +217,7 @@ void OpenGL3_AddColormap(const ImU32* keys, int count, bool qual)
 	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, qual ? GL_NEAREST : GL_LINEAR);
 	glBindTexture(GL_TEXTURE_1D, 0);
 
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx); // PETA AQUI (GImPlot es NULL)
 	Context.ColormapIDs.push_back(texID);
 }
 
@@ -210,16 +233,18 @@ static GLuint CreateHeatmapTexture()
 	return textureID;
 }
 
-void OpenGL3_SetHeatmapData(int plotID, const ImS8* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_BYTE); }
+void SetHeatmapData(int plotID, const ImS8* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_BYTE); }
-void OpenGL3_SetHeatmapData(int plotID, const ImU8* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_BYTE); }
+void SetHeatmapData(int plotID, const ImU8* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_BYTE); }
-void OpenGL3_SetHeatmapData(int plotID, const ImS16* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_SHORT); }
+void SetHeatmapData(int plotID, const ImS16* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_SHORT); }
-void OpenGL3_SetHeatmapData(int plotID, const ImU16* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_SHORT); }
+void SetHeatmapData(int plotID, const ImU16* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_SHORT); }
-void OpenGL3_SetHeatmapData(int plotID, const ImS32* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_INT); }
+void SetHeatmapData(int plotID, const ImS32* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_INT); }
-void OpenGL3_SetHeatmapData(int plotID, const ImU32* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_INT); }
+void SetHeatmapData(int plotID, const ImU32* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_UNSIGNED_INT); }
-void OpenGL3_SetHeatmapData(int plotID, const float* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_FLOAT); }
+void SetHeatmapData(int plotID, const float* values, int rows, int cols) { SetTextureData(plotID, values, rows, cols, GL_FLOAT); }
 
-void OpenGL3_SetHeatmapData(int plotID, const double* values, int rows, int cols)
+void SetHeatmapData(int plotID, const double* values, int rows, int cols)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	if(Context.temp1.Size < rows * cols)
 		Context.temp1.resize(rows * cols);
 
@@ -229,8 +254,10 @@ void OpenGL3_SetHeatmapData(int plotID, const double* values, int rows, int cols
 	SetTextureData(plotID, Context.temp1.Data, rows, cols, GL_FLOAT);
 }
 
-void OpenGL3_SetHeatmapData(int plotID, const ImS64* values, int rows, int cols)
+void SetHeatmapData(int plotID, const ImS64* values, int rows, int cols)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	if(Context.temp2.Size < rows * cols)
 		Context.temp2.resize(rows * cols);
 
@@ -240,8 +267,10 @@ void OpenGL3_SetHeatmapData(int plotID, const ImS64* values, int rows, int cols)
 	SetTextureData(plotID, Context.temp2.Data, rows, cols, GL_INT);
 }
 
-void OpenGL3_SetHeatmapData(int plotID, const ImU64* values, int rows, int cols)
+void SetHeatmapData(int plotID, const ImU64* values, int rows, int cols)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	if(Context.temp3.Size < rows * cols)
 		Context.temp3.resize(rows * cols);
 
@@ -251,8 +280,9 @@ void OpenGL3_SetHeatmapData(int plotID, const ImU64* values, int rows, int cols)
 	SetTextureData(plotID, Context.temp3.Data, rows, cols, GL_UNSIGNED_INT);
 }
 
-void OpenGL3_RenderHeatmap(int plotID, ImDrawList& DrawList, const ImVec2& bounds_min, const ImVec2& bounds_max, float scale_min, float scale_max, ImPlotColormap colormap)
+void RenderHeatmap(int plotID, ImDrawList& DrawList, const ImVec2& bounds_min, const ImVec2& bounds_max, float scale_min, float scale_max, ImPlotColormap colormap)
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
 	int idx = Context.PlotIDs.GetInt(plotID, -1);
 
 	if(idx < 0)
@@ -285,8 +315,10 @@ void OpenGL3_RenderHeatmap(int plotID, ImDrawList& DrawList, const ImVec2& bound
 	DrawList.AddCallback(ImDrawCallback_ResetRenderState, nullptr);
 }
 
-void OpenGL3_BustPlotCache()
+void BustPlotCache()
 {
+    ContextData& Context = *((ContextData*)GImPlot->backendCtx);
+
 	for(const HeatmapData& data : Context.HeatmapDataList)
 		glDeleteTextures(1, &data.HeatmapTexID);
 
@@ -294,6 +326,8 @@ void OpenGL3_BustPlotCache()
 	Context.PlotIDs.Clear();
 }
 
+void BustItemCache() {}
+
 }
 }
 

implot.cpp

@@ -88,16 +88,6 @@ You can read releases logs https://github.com/epezent/implot/releases for more d
 #define GetBufSize GetSize          // A little bit ugly since 'GetBufSize' could technically be used elsewhere (but currently isn't). Could use a proxy define if needed.
 #endif
 
-#ifdef IMPLOT_ENABLE_OPENGL3_ACCELERATION
-namespace ImPlot {
-namespace Backends {
-
-void OpenGL3_BustPlotCache();
-
-}
-}
-#endif
-
 // Global plot context
 ImPlotContext* GImPlot = NULL;
 
@@ -384,13 +374,15 @@ void SetImGuiContext(ImGuiContext* ctx) {
 
 ImPlotContext* CreateContext() {
     ImPlotContext* ctx = IM_NEW(ImPlotContext)();
-    Initialize(ctx);
     if (GImPlot == NULL)
         SetCurrentContext(ctx);
+    ctx->backendCtx = Backend::CreateContext();
+    Initialize(ctx);
     return ctx;
 }
 
 void DestroyContext(ImPlotContext* ctx) {
+    Backend::DestroyContext();
     if (ctx == NULL)
         ctx = GImPlot;
     if (GImPlot == ctx)
@@ -498,9 +490,7 @@ ImPlotPlot* GetCurrentPlot() {
 
 void BustPlotCache() {
     GImPlot->Plots.Clear();
-#ifdef IMPLOT_ENABLE_OPENGL3_ACCELERATION
+    Backend::BustPlotCache();
-    Backends::OpenGL3_BustPlotCache();
-#endif
 }
 
 void PushLinkedAxis(ImPlotAxis& axis) {

implot_internal.h

@@ -37,21 +37,12 @@
 
 #include <time.h>
 #include "imgui_internal.h"
+#include "backends/implot_gpu.h"
 
 #ifndef IMPLOT_VERSION
 #error Must include implot.h before implot_internal.h
 #endif
 
-#ifdef IMPLOT_ENABLE_OPENGL3_ACCELERATION
-namespace ImPlot {
-namespace Backends {
-
-void OpenGL3_AddColormap(const ImU32* keys, int count, bool qual);
-
-}
-}
-#endif
-
 //-----------------------------------------------------------------------------
 // [SECTION] Constants
 //-----------------------------------------------------------------------------
@@ -386,9 +377,7 @@ struct ImPlotColormapData {
         int idx = Count++;
         Map.SetInt(id,idx);
         _AppendTable(idx);
-#ifdef IMPLOT_ENABLE_OPENGL3_ACCELERATION
+        ImPlot::Backend::AddColormap(keys, count, qual);
-        ImPlot::Backends::OpenGL3_AddColormap(keys, count, qual);
-#endif
         return idx;
     }
 
@@ -929,6 +918,9 @@ struct ImPlotContext {
     ImPlotNextItemData NextItemData;
     ImPlotInputMap     InputMap;
     ImPlotPoint        MousePos[IMPLOT_Y_AXES];
+
+    // Backend
+    void* backendCtx;
 };
 
 //-----------------------------------------------------------------------------

implot_items.cpp

@@ -24,6 +24,7 @@
 
 #include "implot.h"
 #include "implot_internal.h"
+#include "backends/implot_gpu.h"
 
 #ifdef _MSC_VER
 #define sprintf sprintf_s
@@ -53,26 +54,6 @@
 #endif
 
 
-#ifdef IMPLOT_ENABLE_OPENGL3_ACCELERATION
-namespace ImPlot {
-namespace Backends {
-    void OpenGL3_SetHeatmapData(int texID, const ImS8* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImU8* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImS16* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImU16* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImS32* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImU32* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImS64* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const ImU64* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const float* values, int rows, int cols);
-    void OpenGL3_SetHeatmapData(int texID, const double* values, int rows, int cols);
-
-    void OpenGL3_RenderHeatmap(int plotID, ImDrawList& DrawList, const ImVec2& bounds_min, const ImVec2& bounds_max, float scale_min, float scale_max, ImPlotColormap colormap);
-}
-}
-#endif
-
-
 namespace ImPlot {
 
 //-----------------------------------------------------------------------------
@@ -158,6 +139,7 @@ void HideNextItem(bool hidden, ImGuiCond cond) {
 
 void BustItemCache() {
     ImPlotContext& gp = *GImPlot;
+    Backend::BustItemCache();
     for (int p = 0; p < gp.Plots.GetBufSize(); ++p) {
         ImPlotPlot& plot = *gp.Plots.GetByIndex(p);
         plot.ColormapIdx = 0;
@@ -1915,8 +1897,8 @@ void RenderHeatmap(Transformer transformer, ImDrawList& DrawList, const T* value
     ImVec2 bmin = transformer(bounds_min);
     ImVec2 bmax = transformer(bounds_max);
 
-    Backends::OpenGL3_RenderHeatmap(gp.CurrentPlot->ID, DrawList, bmin, bmax, scale_min, scale_max, gp.Style.Colormap);
+    Backend::RenderHeatmap(gp.CurrentPlot->ID, DrawList, bmin, bmax, scale_min, scale_max, gp.Style.Colormap);
-    Backends::OpenGL3_SetHeatmapData(gp.CurrentPlot->ID, values, rows, cols);
+    Backend::SetHeatmapData(gp.CurrentPlot->ID, values, rows, cols);
 #else
     GetterHeatmap<T> getter(values, rows, cols, scale_min, scale_max, (bounds_max.x - bounds_min.x) / cols, (bounds_max.y - bounds_min.y) / rows, bounds_min.x, yref, ydir);
     switch (GetCurrentScale()) {