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implot/backends/implot_impl_opengl3.cpp
2021-06-24 17:32:54 +02:00

391 lines
17 KiB
C++

#ifdef IMPLOT_BACKEND_ENABLE_OPENGL3
#include "../implot.h"
#include "../implot_internal.h"
#include "implot_backend.h"
#include "implot_impl_opengl3.h"
#if defined(IMGUI_IMPL_OPENGL_ES2)
#include <GLES2/gl2.h>
// About Desktop OpenGL function loaders:
// Modern desktop OpenGL doesn't have a standard portable header file to load OpenGL function pointers.
// Helper libraries are often used for this purpose! Here we are supporting a few common ones (gl3w, glew, glad).
// You may use another loader/header of your choice (glext, glLoadGen, etc.), or chose to manually implement your own.
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GL3W)
#include <GL/gl3w.h> // Initialize with gl3wInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLEW)
#include <GL/glew.h> // Initialize with glewInit()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD)
#include <glad/glad.h> // Initialize with gladLoadGL()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLAD2)
#include <glad/gl.h> // Initialize with gladLoadGL(...) or gladLoaderLoadGL()
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING2)
#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
#include <glbinding/Binding.h> // Initialize with glbinding::Binding::initialize()
#include <glbinding/gl/gl.h>
using namespace gl;
#elif defined(IMGUI_IMPL_OPENGL_LOADER_GLBINDING3)
#define GLFW_INCLUDE_NONE // GLFW including OpenGL headers causes ambiguity or multiple definition errors.
#include <glbinding/glbinding.h>// Initialize with glbinding::initialize()
#include <glbinding/gl/gl.h>
using namespace gl;
#else
#include IMGUI_IMPL_OPENGL_LOADER_CUSTOM
#endif
namespace ImPlot {
namespace Backend {
struct HeatmapShader
{
GLuint ID = 0; ///< Shader ID for the heatmap shader
GLuint AttribLocationProjection = 0; ///< Attribute location for the projection matrix uniform
GLuint AttribLocationMinValue = 0; ///< Attribute location for the minimum value uniform
GLuint AttribLocationMaxValue = 0; ///< Attribute location for the maximum value uniform
GLuint AttribLocationAxisLog = 0; ///< Attribute location for the logarithmic axes uniform
GLuint AttribLocationMinBounds = 0; ///< Attribute location for the minimum bounds uniform
GLuint AttribLocationMaxBounds = 0; ///< Attribute location for the maximum bounds uniform
};
struct HeatmapData
{
HeatmapShader* ShaderProgram; ///< Shader to be used by this heatmap (either ShaderInt or ShaderFloat)
GLuint HeatmapTexID; ///< Texture ID of the heatmap 2D texture
GLuint ColormapTexID; ///< Texture ID of the colormap 1D texture
ImVec2 MinBounds; ///< Minimum bounds of the heatmap
ImVec2 MaxBounds; ///< Maximum bounds of the heatmap
float MinValue; ///< Minimum value of the colormap
float MaxValue; ///< Maximum value of the colormap
bool AxisLogX; ///< Whether the X axis is logarithmic or not
bool AxisLogY; ///< Whether the Y axis is logarithmic or not
};
struct ContextData
{
HeatmapShader ShaderInt; ///< Shader for integer heatmaps
HeatmapShader ShaderFloat; ///< Shader for floating-point heatmaps
GLuint AttribLocationImGuiProjection = 0; ///< Attribute location for the projection matrix uniform (ImGui default shader)
GLuint ImGuiShader = 0; ///< Shader ID of ImGui's default shader
ImVector<HeatmapData> HeatmapDataList; ///< Array of heatmap data
ImVector<GLuint> ColormapIDs; ///< Texture IDs of the colormap textures
ImGuiStorage ItemIDs; ///< PlotID <-> Heatmap array index table
ImVector<float> temp1; ///< Temporary data
ImVector<ImS32> temp2; ///< Temporary data
ImVector<ImU32> temp3; ///< Temporary data
};
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);
glDeleteProgram(Context.ShaderInt.ID);
glDeleteProgram(Context.ShaderFloat.ID);
Context.HeatmapDataList.clear();
Context.ItemIDs.Clear();
}
#define HEATMAP_VERTEX_SHADER_CODE \
"#version 330 core\n" \
"precision mediump float;\n" \
"layout (location = %d) in vec2 Position;\n" \
"layout (location = %d) in vec2 UV;\n" \
"\n" \
"uniform mat4 ProjMtx;\n" \
"out vec2 Frag_UV;\n" \
"\n" \
"void main()\n" \
"{\n" \
" Frag_UV = UV;\n" \
" gl_Position = ProjMtx * vec4(Position.xy, 0.0f, 1.0f);\n" \
"}\n"
#define HEATMAP_FRAGMENT_SHADER_CODE \
"#version 330 core\n" \
"precision mediump float;\n" \
"\n" \
"in vec2 Frag_UV;\n" \
"out vec4 Out_Color;\n" \
"\n" \
"uniform sampler1D colormap;\n" \
"uniform %csampler2D heatmap;\n" \
"uniform float min_val;\n" \
"uniform float max_val;\n" \
"\n" \
"uniform vec2 bounds_min;\n" \
"uniform vec2 bounds_max;\n" \
"uniform bvec2 ax_log;\n" \
"\n" \
"float log_den(float x, float min_rng, float max_rng)\n" \
"{\n" \
" float minrl = log(min_rng);\n" \
" float maxrl = log(max_rng);\n" \
"\n" \
" return (exp((maxrl - minrl) * x + minrl) - min_rng) / (max_rng - min_rng);" \
"}\n" \
"\n" \
"void main()\n" \
"{\n" \
" float uv_x = ax_log.x ? log_den(Frag_UV.x, bounds_min.x, bounds_max.x) : Frag_UV.x;\n" \
" float uv_y = ax_log.y ? log_den(Frag_UV.y, bounds_min.y, bounds_max.y) : Frag_UV.y;\n" \
"\n" \
" float value = float(texture(heatmap, vec2(uv_x, uv_y)).r);\n" \
" float offset = (value - min_val) / (max_val - min_val);\n" \
" Out_Color = texture(colormap, clamp(offset, 0.0f, 1.0f));\n" \
"}\n"
static void CompileShader(HeatmapShader& ShaderProgram, GLchar* VertexShaderCode, GLchar* FragmentShaderCode)
{
GLuint VertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(VertexShader, 1, &VertexShaderCode, nullptr);
glCompileShader(VertexShader);
GLuint FragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(FragmentShader, 1, &FragmentShaderCode, nullptr);
glCompileShader(FragmentShader);
ShaderProgram.ID = glCreateProgram();
glAttachShader(ShaderProgram.ID, VertexShader);
glAttachShader(ShaderProgram.ID, FragmentShader);
glLinkProgram(ShaderProgram.ID);
glDetachShader(ShaderProgram.ID, VertexShader);
glDetachShader(ShaderProgram.ID, FragmentShader);
glDeleteShader(VertexShader);
glDeleteShader(FragmentShader);
ShaderProgram.AttribLocationProjection = glGetUniformLocation(ShaderProgram.ID, "ProjMtx");
ShaderProgram.AttribLocationMinValue = glGetUniformLocation(ShaderProgram.ID, "min_val");
ShaderProgram.AttribLocationMaxValue = glGetUniformLocation(ShaderProgram.ID, "max_val");
ShaderProgram.AttribLocationMinBounds = glGetUniformLocation(ShaderProgram.ID, "bounds_min");
ShaderProgram.AttribLocationMaxBounds = glGetUniformLocation(ShaderProgram.ID, "bounds_max");
ShaderProgram.AttribLocationAxisLog = glGetUniformLocation(ShaderProgram.ID, "ax_log");
glUseProgram(ShaderProgram.ID);
glUniform1i(glGetUniformLocation(ShaderProgram.ID, "heatmap"), 0); // Set texture slot of heatmap texture
glUniform1i(glGetUniformLocation(ShaderProgram.ID, "colormap"), 1); // Set texture slot of colormap texture
}
static void CreateHeatmapShader(const ImDrawList*, const ImDrawCmd*)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
glGetIntegerv(GL_CURRENT_PROGRAM, (GLint*)&Context.ImGuiShader);
Context.AttribLocationImGuiProjection = glGetUniformLocation(Context.ImGuiShader, "ProjMtx");
GLuint AttribLocationVtxPos = (GLuint)glGetAttribLocation(Context.ImGuiShader, "Position");
GLuint AttribLocationVtxUV = (GLuint)glGetAttribLocation(Context.ImGuiShader, "UV");
GLchar* VertexShaderCode = new GLchar[1000];
GLchar* FragmentShaderCode = new GLchar[1000];
snprintf(VertexShaderCode, 1000, HEATMAP_VERTEX_SHADER_CODE, AttribLocationVtxPos, AttribLocationVtxUV);
snprintf(FragmentShaderCode, 1000, HEATMAP_FRAGMENT_SHADER_CODE, ' ');
CompileShader(Context.ShaderFloat, VertexShaderCode, FragmentShaderCode);
snprintf(VertexShaderCode, 1000, HEATMAP_VERTEX_SHADER_CODE, AttribLocationVtxPos, AttribLocationVtxUV);
snprintf(FragmentShaderCode, 1000, HEATMAP_FRAGMENT_SHADER_CODE, 'i');
CompileShader(Context.ShaderInt, VertexShaderCode, FragmentShaderCode);
glUseProgram(0);
delete[] VertexShaderCode;
delete[] FragmentShaderCode;
}
static void RenderCallback(const ImDrawList*, const ImDrawCmd* cmd)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
int itemID = (int)(intptr_t)cmd->UserCallbackData;
int plotIdx = Context.ItemIDs.GetInt(itemID, -1);
HeatmapData& data = Context.HeatmapDataList[plotIdx];
// Get projection matrix of current shader
float OrthoProjection[4][4];
glGetUniformfv(Context.ImGuiShader, Context.AttribLocationImGuiProjection, &OrthoProjection[0][0]);
// Enable our shader
glUseProgram(data.ShaderProgram->ID);
glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, data.HeatmapTexID); // Set texture ID of data
glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_1D, data.ColormapTexID); // Set texture ID of colormap
glUniformMatrix4fv(data.ShaderProgram->AttribLocationProjection, 1, GL_FALSE, &OrthoProjection[0][0]);
glUniform1f(data.ShaderProgram->AttribLocationMinValue, data.MinValue); // Set minimum range
glUniform1f(data.ShaderProgram->AttribLocationMaxValue, data.MaxValue); // Set maximum range
glUniform2i(data.ShaderProgram->AttribLocationAxisLog, data.AxisLogX, data.AxisLogY); // Logarithmic axis
glUniform2f(data.ShaderProgram->AttribLocationMinBounds, data.MinBounds.x, data.MinBounds.y); // Set minimum bounds
glUniform2f(data.ShaderProgram->AttribLocationMaxBounds, data.MaxBounds.x, data.MaxBounds.y); // Set maximum bounds
}
static void ResetState(const ImDrawList*, const ImDrawCmd*)
{
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, 0);
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
glUseProgram(Context.ImGuiShader);
}
static void SetTextureData(int itemID, const void* data, GLsizei rows, GLsizei cols, GLint internalFormat, GLenum format, GLenum type)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
int idx = Context.ItemIDs.GetInt(itemID, -1);
GLuint texID = Context.HeatmapDataList[idx].HeatmapTexID;
Context.HeatmapDataList[idx].ShaderProgram = (type == GL_FLOAT ? &Context.ShaderFloat : &Context.ShaderInt);
// Set heatmap data
glBindTexture(GL_TEXTURE_2D, texID);
glTexImage2D(GL_TEXTURE_2D, 0, internalFormat, cols, rows, 0, format, type, data);
}
void AddColormap(const ImU32* keys, int count, bool qual)
{
GLuint textureID;
glGenTextures(1, &textureID);
glBindTexture(GL_TEXTURE_1D, textureID);
glTexImage1D(GL_TEXTURE_1D, 0, GL_RGBA, count, 0, GL_RGBA, GL_UNSIGNED_BYTE, keys);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, qual ? GL_NEAREST : GL_LINEAR);
glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, qual ? GL_NEAREST : GL_LINEAR);
glBindTexture(GL_TEXTURE_1D, 0);
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
Context.ColormapIDs.push_back(textureID);
}
static GLuint CreateHeatmapTexture()
{
GLuint textureID;
glGenTextures(1, &textureID);
glBindTexture(GL_TEXTURE_2D, textureID);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glBindTexture(GL_TEXTURE_2D, 0);
return textureID;
}
void SetHeatmapData(int itemID, const ImS8* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R8I, GL_RED_INTEGER, GL_BYTE); }
void SetHeatmapData(int itemID, const ImU8* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R8UI, GL_RED_INTEGER, GL_UNSIGNED_BYTE); }
void SetHeatmapData(int itemID, const ImS16* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R16I, GL_RED_INTEGER, GL_SHORT); }
void SetHeatmapData(int itemID, const ImU16* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R16UI, GL_RED_INTEGER, GL_UNSIGNED_SHORT); }
void SetHeatmapData(int itemID, const ImS32* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R32I, GL_RED_INTEGER, GL_INT); }
void SetHeatmapData(int itemID, const ImU32* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R32UI, GL_RED_INTEGER, GL_UNSIGNED_INT); }
void SetHeatmapData(int itemID, const float* values, int rows, int cols) { SetTextureData(itemID, values, rows, cols, GL_R32F, GL_RED, GL_FLOAT); }
void SetHeatmapData(int itemID, const double* values, int rows, int cols)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
if(Context.temp1.Size < rows * cols)
Context.temp1.resize(rows * cols);
for(int i = 0; i < rows*cols; i++)
Context.temp1[i] = (float)values[i];
SetTextureData(itemID, Context.temp1.Data, rows, cols, GL_R32F, GL_RED, GL_FLOAT);
}
void SetHeatmapData(int itemID, const ImS64* values, int rows, int cols)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
if(Context.temp2.Size < rows * cols)
Context.temp2.resize(rows * cols);
for(int i = 0; i < rows*cols; i++)
Context.temp2[i] = (ImS32)values[i];
SetTextureData(itemID, Context.temp2.Data, rows, cols, GL_R32I, GL_RED_INTEGER, GL_INT);
}
void SetHeatmapData(int itemID, const ImU64* values, int rows, int cols)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
if(Context.temp3.Size < rows * cols)
Context.temp3.resize(rows * cols);
for(int i = 0; i < rows*cols; i++)
Context.temp3[i] = (ImU32)values[i];
SetTextureData(itemID, Context.temp3.Data, rows, cols, GL_R32UI, GL_RED_INTEGER, GL_UNSIGNED_INT);
}
void SetAxisLog(int itemID, bool x_is_log, bool y_is_log, const ImVec2& bounds_min, const ImVec2& bounds_max)
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
int idx = Context.ItemIDs.GetInt(itemID, -1);
HeatmapData& data = Context.HeatmapDataList[idx];
data.AxisLogX = x_is_log;
data.AxisLogY =y_is_log;
data.MinBounds = bounds_min;
data.MaxBounds = bounds_max;
}
void RenderHeatmap(int itemID, 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.ItemIDs.GetInt(itemID, Context.HeatmapDataList.Size);
if(idx == Context.HeatmapDataList.Size)
{
// New entry
Context.ItemIDs.SetInt(itemID, Context.HeatmapDataList.Size);
Context.HeatmapDataList.push_back(HeatmapData());
Context.HeatmapDataList[idx].HeatmapTexID = CreateHeatmapTexture();
}
HeatmapData& data = Context.HeatmapDataList[idx];
data.ColormapTexID = Context.ColormapIDs[colormap];
data.MinValue = scale_min;
data.MaxValue = scale_max;
if(Context.ShaderInt.ID == 0 || Context.ShaderFloat.ID == 0)
DrawList.AddCallback(CreateHeatmapShader, nullptr);
DrawList.AddCallback(RenderCallback, (void*)(intptr_t)itemID);
DrawList.PrimReserve(6, 4);
DrawList.PrimRectUV(bounds_min, bounds_max, ImVec2(0.0f, 1.0f), ImVec2(1.0f, 0.0f), 0);
DrawList.AddCallback(ResetState, nullptr);
}
void BustPlotCache()
{
ContextData& Context = *((ContextData*)GImPlot->backendCtx);
for(const HeatmapData& data : Context.HeatmapDataList)
glDeleteTextures(1, &data.HeatmapTexID);
Context.HeatmapDataList.clear();
Context.ItemIDs.Clear();
}
void BustItemCache() {}
}
}
#endif