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Examples: OpenGL3: Added shaders more versions of GLSL + made the example app default to GL 3.0 + GLSL 130 (instead of GL 3.2 + GLSL 150) unless on Mac. (#1938, #1900, #1513, #1466, etc.)

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omar
2018-07-10 18:29:57 +02:00
parent b829671df1
commit fff014dfed
6 changed files with 120 additions and 26 deletions
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92
examples/imgui_impl_opengl3.cpp
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@ -11,7 +11,7 @@
// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
// 2018-07-10: OpenGL: Added error output when shaders fail to compile/link.
// 2018-07-10: OpenGL: Support for more GLSL versions (based on the GLSL version string). Added error output when shaders fail to compile/link.
// 2018-06-08: Misc: Extracted imgui_impl_opengl3.cpp/.h away from the old combined GLFW/SDL+OpenGL3 examples.
// 2018-06-08: OpenGL: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
// 2018-05-25: OpenGL: Removed unnecessary backup/restore of GL_ELEMENT_ARRAY_BUFFER_BINDING since this is part of the VAO state.
@ -26,6 +26,24 @@
// 2016-09-05: OpenGL: Fixed save and restore of current scissor rectangle.
// 2016-07-29: OpenGL: Explicitly setting GL_UNPACK_ROW_LENGTH to reduce issues because SDL changes it. (#752)
//----------------------------------------
// OpenGL GLSL GLSL
// version version string
//----------------------------------------
// 2.0 110 "#version 110"
// 2.1 120
// 3.0 130
// 3.1 140
// 3.2 150 "#version 150"
// 3.3 330
// 4.0 400
// 4.1 410
// 4.2 420
// 4.3 430
// ES 2.0 100 "#version 100"
// ES 3.0 300 "#version 300 es"
//----------------------------------------
#if defined(_MSC_VER) && !defined(_CRT_SECURE_NO_WARNINGS)
#define _CRT_SECURE_NO_WARNINGS
#endif
@ -40,7 +58,7 @@
//#include <glad/glad.h>
// OpenGL Data
static char g_GlslVersion[32] = "";
static char g_GlslVersionString[32] = "";
static GLuint g_FontTexture = 0;
static GLuint g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0;
static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0;
@ -52,10 +70,10 @@ bool ImGui_ImplOpenGL3_Init(const char* glsl_version)
{
// Store GLSL version string so we can refer to it later in case we recreate shaders. Note: GLSL version is NOT the same as GL version. Leave this to NULL if unsure.
if (glsl_version == NULL)
glsl_version = "#version 150";
IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersion));
strcpy(g_GlslVersion, glsl_version);
strcat(g_GlslVersion, "\n");
glsl_version = "#version 130";
IM_ASSERT((int)strlen(glsl_version) + 2 < IM_ARRAYSIZE(g_GlslVersionString));
strcpy(g_GlslVersionString, glsl_version);
strcat(g_GlslVersionString, "\n");
return true;
}
@ -285,8 +303,25 @@ bool ImGui_ImplOpenGL3_CreateDeviceObjects()
glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer);
glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array);
// Create shaders
const GLchar* vertex_shader =
// Parse GLSL version string
int glsl_version = 130;
sscanf(g_GlslVersionString, "#version %d", &glsl_version);
const GLchar* vertex_shader_glsl_120 =
"uniform mat4 ProjMtx;\n"
"attribute vec2 Position;\n"
"attribute vec2 UV;\n"
"attribute vec4 Color;\n"
"varying vec2 Frag_UV;\n"
"varying 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* vertex_shader_glsl_130 =
"uniform mat4 ProjMtx;\n"
"in vec2 Position;\n"
"in vec2 UV;\n"
@ -295,28 +330,55 @@ bool ImGui_ImplOpenGL3_CreateDeviceObjects()
"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"
" Frag_UV = UV;\n"
" Frag_Color = Color;\n"
" gl_Position = ProjMtx * vec4(Position.xy,0,1);\n"
"}\n";
const GLchar* fragment_shader =
const GLchar* fragment_shader_glsl_120 =
"#ifdef GL_ES\n"
" precision mediump float;\n"
"#endif\n"
"uniform sampler2D Texture;\n"
"varying vec2 Frag_UV;\n"
"varying vec4 Frag_Color;\n"
"void main()\n"
"{\n"
" gl_FragColor = Frag_Color * texture2D(Texture, Frag_UV.st);\n"
"}\n";
const GLchar* fragment_shader_glsl_130 =
"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"
" Out_Color = Frag_Color * texture(Texture, Frag_UV.st);\n"
"}\n";
const GLchar* vertex_shader_with_version[2] = { g_GlslVersion, vertex_shader };
// Select shaders matching our GLSL versions
const GLchar* vertex_shader = NULL;
const GLchar* fragment_shader = NULL;
if (glsl_version < 130)
{
vertex_shader = vertex_shader_glsl_120;
fragment_shader = fragment_shader_glsl_120;
}
else
{
vertex_shader = vertex_shader_glsl_130;
fragment_shader = fragment_shader_glsl_130;
}
// Create shaders
const GLchar* vertex_shader_with_version[2] = { g_GlslVersionString, vertex_shader };
g_VertHandle = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(g_VertHandle, 2, vertex_shader_with_version, NULL);
glCompileShader(g_VertHandle);
CheckShader(g_VertHandle, "vertex shader");
const GLchar* fragment_shader_with_version[2] = { g_GlslVersion, fragment_shader };
const GLchar* fragment_shader_with_version[2] = { g_GlslVersionString, fragment_shader };
g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(g_FragHandle, 2, fragment_shader_with_version, NULL);
glCompileShader(g_FragHandle);