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gltext.h
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// Repository: https://github.com/MrVallentin/glText
// License: https://github.com/MrVallentin/glText/blob/master/LICENSE.md
//
// Date Created: September 24, 2013
// Last Modified: November 03, 2019
// In one C or C++ file, define GLT_IMPLEMENTATION prior to inclusion to create the implementation.
// #define GLT_IMPLEMENTATION
// #include "gltext.h"
// Copyright (c) 2018-2019 Robert Pancoast
// Support OpenGLES
//
// Copyright (c) 2013-2018 Christian Vallentin
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would be
// appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
// be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
// Refrain from using any exposed macros, functions
// or structs prefixed with an underscore. As these
// are only intended for internal purposes. Which
// additionally means they can be removed, renamed
// or changed between minor updates without notice.
#ifndef GL_TEXT_H
#define GL_TEXT_H
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(__gl_h_) && !defined(__glcorearb_h_) && !defined(USE_GLES)
# error OpenGL header must be included prior to including glText header
#endif
#include <stdlib.h> /* malloc(), calloc(), free() */
#include <string.h> /* memset(), memcpy(), strlen() */
#include <stdint.h> /* uint8_t, uint16_t, uint32_t, uint64_t */
#if (defined(_DEBUG) || defined(DEBUG)) && !defined(GLT_DEBUG)
# define GLT_DEBUG 1
#endif
#ifdef GLT_DEBUG
# include <assert.h> /* assert() */
# define _GLT_ASSERT(expression) assert(expression)
#else
# define _GLT_ASSERT(expression)
#endif
#ifdef GLT_DEBUG_PRINT
# include <stdio.h> /* printf */
#endif
#define _GLT_STRINGIFY(str) #str
#define _GLT_STRINGIFY_TOKEN(str) _GLT_STRINGIFY(str)
#define GLT_STRINGIFY_VERSION(major, minor, patch) _GLT_STRINGIFY(major) "." _GLT_STRINGIFY(minor) "." _GLT_STRINGIFY(patch)
#define GLT_NAME "glText"
#define GLT_VERSION_MAJOR 1
#define GLT_VERSION_MINOR 1
#define GLT_VERSION_PATCH 6
#define GLT_VERSION GLT_STRINGIFY_VERSION(GLT_VERSION_MAJOR, GLT_VERSION_MINOR, GLT_VERSION_PATCH)
#define GLT_NAME_VERSION GLT_NAME " " GLT_VERSION
#define GLT_NULL 0
#define GLT_NULL_HANDLE 0
#ifdef GLT_IMPORTS
# define GLT_API extern
#else
# ifndef GLT_STATIC
# define GLT_STATIC
# endif
# define GLT_API static
#endif
#define GLT_LEFT 0
#define GLT_TOP 0
#define GLT_CENTER 1
#define GLT_RIGHT 2
#define GLT_BOTTOM 2
static GLboolean gltInitialized = GL_FALSE;
typedef struct GLTtext GLTtext;
GLT_API GLboolean gltInit(void);
GLT_API void gltTerminate(void);
GLT_API GLTtext* gltCreateText(void);
GLT_API void gltDeleteText(GLTtext *text);
#define gltDestroyText gltDeleteText
GLT_API GLboolean gltSetText(GLTtext *text, const char *string);
GLT_API const char* gltGetText(GLTtext *text);
GLT_API void gltViewport(GLsizei width, GLsizei height);
GLT_API void gltBeginDraw();
GLT_API void gltEndDraw();
GLT_API void gltDrawText(GLTtext *text, const GLfloat mvp[16]);
GLT_API void gltDrawText2D(GLTtext *text, GLfloat x, GLfloat y, GLfloat scale);
GLT_API void gltDrawText2DAligned(GLTtext *text, GLfloat x, GLfloat y, GLfloat scale, int horizontalAlignment, int verticalAlignment);
GLT_API void gltDrawText3D(GLTtext *text, GLfloat x, GLfloat y, GLfloat z, GLfloat scale, GLfloat view[16], GLfloat projection[16]);
GLT_API void gltColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a);
GLT_API void gltGetColor(GLfloat *r, GLfloat *g, GLfloat *b, GLfloat *a);
GLT_API GLfloat gltGetLineHeight(GLfloat scale);
GLT_API GLfloat gltGetTextWidth(const GLTtext *text, GLfloat scale);
GLT_API GLfloat gltGetTextHeight(const GLTtext *text, GLfloat scale);
GLT_API GLboolean gltIsCharacterSupported(const char c);
GLT_API GLint gltCountSupportedCharacters(const char *str);
GLT_API GLboolean gltIsCharacterDrawable(const char c);
GLT_API GLint gltCountDrawableCharacters(const char *str);
GLT_API GLint gltCountNewLines(const char *str);
// After this point everything you'll see is the
// implementation and all the internal stuff.
// Use it at your own discretion, but be warned
// that everything can have changed in the next
// commit, so be careful relying on any of it.
#ifdef GLT_IMPLEMENTATION
#define _GLT_TEXT2D_POSITION_LOCATION 0
#define _GLT_TEXT2D_TEXCOORD_LOCATION 1
#define _GLT_TEXT2D_POSITION_SIZE 2
#define _GLT_TEXT2D_TEXCOORD_SIZE 2
#define _GLT_TEXT2D_VERTEX_SIZE (_GLT_TEXT2D_POSITION_SIZE + _GLT_TEXT2D_TEXCOORD_SIZE)
#define _GLT_TEXT2D_POSITION_OFFSET 0
#define _GLT_TEXT2D_TEXCOORD_OFFSET _GLT_TEXT2D_POSITION_SIZE
#define _GLT_MAT4_INDEX(row, column) ((row) + (column) * 4)
static const char *_gltFontGlyphCharacters = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789.,!?-+/():;%&`*#=[]\"";
#define _gltFontGlyphCount 83
#define _gltFontGlyphMinChar ' '
#define _gltFontGlyphMaxChar 'z'
static const int _gltFontGlyphHeight = 17; // Line height
typedef struct _GLTglyph {
char c;
GLint x, y;
GLint w, h;
GLfloat u1, v1;
GLfloat u2, v2;
GLboolean drawable;
} _GLTglyph;
typedef struct _GLTglyphdata {
uint32_t x, y;
uint32_t w, h;
uint32_t marginLeft, marginTop;
uint32_t marginRight, marginBottom;
uint16_t dataWidth, dataHeight;
} _GLTglyphdata;
static _GLTglyph _gltFontGlyphs[_gltFontGlyphCount];
#define _gltFontGlyphLength (_gltFontGlyphMaxChar - _gltFontGlyphMinChar + 1)
static _GLTglyph _gltFontGlyphs2[_gltFontGlyphLength];
static GLuint _gltText2DShader = GLT_NULL_HANDLE;
static GLuint _gltText2DFontTexture = GLT_NULL_HANDLE;
static GLint _gltText2DShaderMVPUniformLocation = -1;
static GLint _gltText2DShaderColorUniformLocation = -1;
static GLfloat _gltText2DProjectionMatrix[16];
struct GLTtext {
char *_text;
GLsizei _textLength;
GLboolean _dirty;
GLsizei vertexCount;
GLfloat *_vertices;
GLuint _vao;
GLuint _vbo;
};
GLT_API void _gltGetViewportSize(GLint *width, GLint *height);
GLT_API void _gltMat4Mult(const GLfloat lhs[16], const GLfloat rhs[16], GLfloat result[16]);
GLT_API void _gltUpdateBuffers(GLTtext *text);
GLT_API GLboolean _gltCreateText2DShader(void);
GLT_API GLboolean _gltCreateText2DFontTexture(void);
GLT_API GLTtext* gltCreateText(void)
{
GLTtext *text = (GLTtext*)calloc(1, sizeof(GLTtext));
_GLT_ASSERT(text);
if (!text)
return GLT_NULL;
glGenVertexArrays(1, &text->_vao);
glGenBuffers(1, &text->_vbo);
_GLT_ASSERT(text->_vao);
_GLT_ASSERT(text->_vbo);
if (!text->_vao || !text->_vbo)
{
gltDeleteText(text);
return GLT_NULL;
}
glBindVertexArray(text->_vao);
glBindBuffer(GL_ARRAY_BUFFER, text->_vbo);
glEnableVertexAttribArray(_GLT_TEXT2D_POSITION_LOCATION);
glVertexAttribPointer(_GLT_TEXT2D_POSITION_LOCATION, _GLT_TEXT2D_POSITION_SIZE, GL_FLOAT, GL_FALSE, (_GLT_TEXT2D_VERTEX_SIZE * sizeof(GLfloat)), (const void*)(_GLT_TEXT2D_POSITION_OFFSET * sizeof(GLfloat)));
glEnableVertexAttribArray(_GLT_TEXT2D_TEXCOORD_LOCATION);
glVertexAttribPointer(_GLT_TEXT2D_TEXCOORD_LOCATION, _GLT_TEXT2D_TEXCOORD_SIZE, GL_FLOAT, GL_FALSE, (_GLT_TEXT2D_VERTEX_SIZE * sizeof(GLfloat)), (const void*)(_GLT_TEXT2D_TEXCOORD_OFFSET * sizeof(GLfloat)));
glBindVertexArray(0);
return text;
}
GLT_API void gltDeleteText(GLTtext *text)
{
if (!text)
return;
if (text->_vao)
{
glDeleteVertexArrays(1, &text->_vao);
text->_vao = GLT_NULL_HANDLE;
}
if (text->_vbo)
{
glDeleteBuffers(1, &text->_vbo);
text->_vbo = GLT_NULL_HANDLE;
}
if (text->_text)
free(text->_text);
if (text->_vertices)
free(text->_vertices);
free(text);
}
GLT_API GLboolean gltSetText(GLTtext *text, const char *string)
{
if (!text)
return GL_FALSE;
int strLength = 0;
if (string)
strLength = strlen(string);
if (strLength)
{
if (text->_text)
{
if (strcmp(string, text->_text) == 0)
return GL_TRUE;
free(text->_text);
text->_text = GLT_NULL;
}
text->_text = (char*)malloc((strLength + 1) * sizeof(char));
if (text->_text)
{
memcpy(text->_text, string, (strLength + 1) * sizeof(char));
text->_textLength = strLength;
text->_dirty = GL_TRUE;
return GL_TRUE;
}
}
else
{
if (text->_text)
{
free(text->_text);
text->_text = GLT_NULL;
}
else
{
return GL_TRUE;
}
text->_textLength = 0;
text->_dirty = GL_TRUE;
return GL_TRUE;
}
return GL_FALSE;
}
GLT_API const char* gltGetText(GLTtext *text)
{
if (text && text->_text)
return text->_text;
return "\0";
}
GLT_API void gltViewport(GLsizei width, GLsizei height)
{
_GLT_ASSERT(width > 0);
_GLT_ASSERT(height > 0);
const GLfloat left = 0.0f;
const GLfloat right = (GLfloat)width;
const GLfloat bottom = (GLfloat)height;
const GLfloat top = 0.0f;
const GLfloat zNear = -1.0f;
const GLfloat zFar = 1.0f;
const GLfloat projection[16] = {
(2.0f / (right - left)), 0.0f, 0.0f, 0.0f,
0.0f, (2.0f / (top - bottom)), 0.0f, 0.0f,
0.0f, 0.0f, (-2.0f / (zFar - zNear)), 0.0f,
-((right + left) / (right - left)),
-((top + bottom) / (top - bottom)),
-((zFar + zNear) / (zFar - zNear)),
1.0f,
};
memcpy(_gltText2DProjectionMatrix, projection, 16 * sizeof(GLfloat));
}
GLT_API void gltBeginDraw()
{
glUseProgram(_gltText2DShader);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, _gltText2DFontTexture);
}
GLT_API void gltEndDraw()
{
}
#define _gltDrawText() \
glUniformMatrix4fv(_gltText2DShaderMVPUniformLocation, 1, GL_FALSE, mvp); \
\
glBindVertexArray(text->_vao); \
glDrawArrays(GL_TRIANGLES, 0, text->vertexCount);
GLT_API void gltDrawText(GLTtext *text, const GLfloat mvp[16])
{
if (!text)
return;
if (text->_dirty)
_gltUpdateBuffers(text);
if (!text->vertexCount)
return;
_gltDrawText();
}
GLT_API void gltDrawText2D(GLTtext *text, GLfloat x, GLfloat y, GLfloat scale)
{
if (!text)
return;
if (text->_dirty)
_gltUpdateBuffers(text);
if (!text->vertexCount)
return;
#ifndef GLT_MANUAL_VIEWPORT
GLint viewportWidth, viewportHeight;
_gltGetViewportSize(&viewportWidth, &viewportHeight);
gltViewport(viewportWidth, viewportHeight);
#endif
const GLfloat model[16] = {
scale, 0.0f, 0.0f, 0.0f,
0.0f, scale, 0.0f, 0.0f,
0.0f, 0.0f, scale, 0.0f,
x, y, 0.0f, 1.0f,
};
GLfloat mvp[16];
_gltMat4Mult(_gltText2DProjectionMatrix, model, mvp);
_gltDrawText();
}
GLT_API void gltDrawText2DAligned(GLTtext *text, GLfloat x, GLfloat y, GLfloat scale, int horizontalAlignment, int verticalAlignment)
{
if (!text)
return;
if (text->_dirty)
_gltUpdateBuffers(text);
if (!text->vertexCount)
return;
if (horizontalAlignment == GLT_CENTER)
x -= gltGetTextWidth(text, scale) * 0.5f;
else if (horizontalAlignment == GLT_RIGHT)
x -= gltGetTextWidth(text, scale);
if (verticalAlignment == GLT_CENTER)
y -= gltGetTextHeight(text, scale) * 0.5f;
else if (verticalAlignment == GLT_RIGHT)
y -= gltGetTextHeight(text, scale);
gltDrawText2D(text, x, y, scale);
}
GLT_API void gltDrawText3D(GLTtext *text, GLfloat x, GLfloat y, GLfloat z, GLfloat scale, GLfloat view[16], GLfloat projection[16])
{
if (!text)
return;
if (text->_dirty)
_gltUpdateBuffers(text);
if (!text->vertexCount)
return;
const GLfloat model[16] = {
scale, 0.0f, 0.0f, 0.0f,
0.0f, -scale, 0.0f, 0.0f,
0.0f, 0.0f, scale, 0.0f,
x, y + (GLfloat)_gltFontGlyphHeight * scale, z, 1.0f,
};
GLfloat mvp[16];
GLfloat vp[16];
_gltMat4Mult(projection, view, vp);
_gltMat4Mult(vp, model, mvp);
_gltDrawText();
}
GLT_API void gltColor(GLfloat r, GLfloat g, GLfloat b, GLfloat a)
{
glUniform4f(_gltText2DShaderColorUniformLocation, r, g, b, a);
}
GLT_API void gltGetColor(GLfloat *r, GLfloat *g, GLfloat *b, GLfloat *a)
{
GLfloat color[4];
glGetUniformfv(_gltText2DShader, _gltText2DShaderColorUniformLocation, color);
if (r) (*r) = color[0];
if (g) (*g) = color[1];
if (b) (*b) = color[2];
if (a) (*a) = color[3];
}
GLT_API GLfloat gltGetLineHeight(GLfloat scale)
{
return (GLfloat)_gltFontGlyphHeight * scale;
}
GLT_API GLfloat gltGetTextWidth(const GLTtext *text, GLfloat scale)
{
if (!text || !text->_text)
return 0.0f;
GLfloat maxWidth = 0.0f;
GLfloat width = 0.0f;
_GLTglyph glyph;
char c;
int i;
for (i = 0; i < text->_textLength; i++)
{
c = text->_text[i];
if ((c == '\n') || (c == '\r'))
{
if (width > maxWidth)
maxWidth = width;
width = 0.0f;
continue;
}
if (!gltIsCharacterSupported(c))
{
#ifdef GLT_UNKNOWN_CHARACTER
c = GLT_UNKNOWN_CHARACTER;
if (!gltIsCharacterSupported(c))
continue;
#else
continue;
#endif
}
glyph = _gltFontGlyphs2[c - _gltFontGlyphMinChar];
width += (GLfloat)glyph.w;
}
if (width > maxWidth)
maxWidth = width;
return maxWidth * scale;
}
GLT_API GLfloat gltGetTextHeight(const GLTtext *text, GLfloat scale)
{
if (!text || !text->_text)
return 0.0f;
return (GLfloat)(gltCountNewLines(text->_text) + 1) * gltGetLineHeight(scale);
}
GLT_API GLboolean gltIsCharacterSupported(const char c)
{
if (c == '\t') return GL_TRUE;
if (c == '\n') return GL_TRUE;
if (c == '\r') return GL_TRUE;
int i;
for (i = 0; i < _gltFontGlyphCount; i++)
{
if (_gltFontGlyphCharacters[i] == c)
return GL_TRUE;
}
return GL_FALSE;
}
GLT_API GLint gltCountSupportedCharacters(const char *str)
{
if (!str)
return 0;
GLint count = 0;
while ((*str) != '\0')
{
if (gltIsCharacterSupported(*str))
count++;
str++;
}
return count;
}
GLT_API GLboolean gltIsCharacterDrawable(const char c)
{
if (c < _gltFontGlyphMinChar) return GL_FALSE;
if (c > _gltFontGlyphMaxChar) return GL_FALSE;
if (_gltFontGlyphs2[c - _gltFontGlyphMinChar].drawable)
return GL_TRUE;
return GL_FALSE;
}
GLT_API GLint gltCountDrawableCharacters(const char *str)
{
if (!str)
return 0;
GLint count = 0;
while ((*str) != '\0')
{
if (gltIsCharacterDrawable(*str))
count++;
str++;
}
return count;
}
GLT_API GLint gltCountNewLines(const char *str)
{
GLint count = 0;
while ((str = strchr(str, '\n')) != NULL)
{
count++;
str++;
}
return count;
}
GLT_API void _gltGetViewportSize(GLint *width, GLint *height)
{
GLint dimensions[4];
glGetIntegerv(GL_VIEWPORT, dimensions);
if (width) (*width) = dimensions[2];
if (height) (*height) = dimensions[3];
}
GLT_API void _gltMat4Mult(const GLfloat lhs[16], const GLfloat rhs[16], GLfloat result[16])
{
int c, r, i;
for (c = 0; c < 4; c++)
{
for (r = 0; r < 4; r++)
{
result[_GLT_MAT4_INDEX(r, c)] = 0.0f;
for (i = 0; i < 4; i++)
result[_GLT_MAT4_INDEX(r, c)] += lhs[_GLT_MAT4_INDEX(r, i)] * rhs[_GLT_MAT4_INDEX(i, c)];
}
}
}
GLT_API void _gltUpdateBuffers(GLTtext *text)
{
if (!text || !text->_dirty)
return;
if (text->_vertices)
{
text->vertexCount = 0;
free(text->_vertices);
text->_vertices = GLT_NULL;
}
if (!text->_text || !text->_textLength)
{
text->_dirty = GL_FALSE;
return;
}
const GLsizei countDrawable = gltCountDrawableCharacters(text->_text);
if (!countDrawable)
{
text->_dirty = GL_FALSE;
return;
}
const GLsizei vertexCount = countDrawable * 2 * 3; // 3 vertices in a triangle, 2 triangles in a quad
const GLsizei vertexSize = _GLT_TEXT2D_VERTEX_SIZE;
GLfloat *vertices = (GLfloat*)malloc(vertexCount * vertexSize * sizeof(GLfloat));
if (!vertices)
return;
GLsizei vertexElementIndex = 0;
GLfloat glyphX = 0.0f;
GLfloat glyphY = 0.0f;
GLfloat glyphWidth;
const GLfloat glyphHeight = (GLfloat)_gltFontGlyphHeight;
const GLfloat glyphAdvanceX = 0.0f;
const GLfloat glyphAdvanceY = 0.0f;
_GLTglyph glyph;
char c;
int i;
for (i = 0; i < text->_textLength; i++)
{
c = text->_text[i];
if (c == '\n')
{
glyphX = 0.0f;
glyphY += glyphHeight + glyphAdvanceY;
continue;
}
else if (c == '\r')
{
glyphX = 0.0f;
continue;
}
if (!gltIsCharacterSupported(c))
{
#ifdef GLT_UNKNOWN_CHARACTER
c = GLT_UNKNOWN_CHARACTER;
if (!gltIsCharacterSupported(c))
continue;
#else
continue;
#endif
}
glyph = _gltFontGlyphs2[c - _gltFontGlyphMinChar];
glyphWidth = (GLfloat)glyph.w;
if (glyph.drawable)
{
vertices[vertexElementIndex++] = glyphX;
vertices[vertexElementIndex++] = glyphY;
vertices[vertexElementIndex++] = glyph.u1;
vertices[vertexElementIndex++] = glyph.v1;
vertices[vertexElementIndex++] = glyphX + glyphWidth;
vertices[vertexElementIndex++] = glyphY + glyphHeight;
vertices[vertexElementIndex++] = glyph.u2;
vertices[vertexElementIndex++] = glyph.v2;
vertices[vertexElementIndex++] = glyphX + glyphWidth;
vertices[vertexElementIndex++] = glyphY;
vertices[vertexElementIndex++] = glyph.u2;
vertices[vertexElementIndex++] = glyph.v1;
vertices[vertexElementIndex++] = glyphX;
vertices[vertexElementIndex++] = glyphY;
vertices[vertexElementIndex++] = glyph.u1;
vertices[vertexElementIndex++] = glyph.v1;
vertices[vertexElementIndex++] = glyphX;
vertices[vertexElementIndex++] = glyphY + glyphHeight;
vertices[vertexElementIndex++] = glyph.u1;
vertices[vertexElementIndex++] = glyph.v2;
vertices[vertexElementIndex++] = glyphX + glyphWidth;
vertices[vertexElementIndex++] = glyphY + glyphHeight;
vertices[vertexElementIndex++] = glyph.u2;
vertices[vertexElementIndex++] = glyph.v2;
}
glyphX += glyphWidth + glyphAdvanceX;
}
text->vertexCount = vertexCount;
text->_vertices = vertices;
glBindBuffer(GL_ARRAY_BUFFER, text->_vbo);
glBufferData(GL_ARRAY_BUFFER, vertexCount * _GLT_TEXT2D_VERTEX_SIZE * sizeof(GLfloat), vertices, GL_DYNAMIC_DRAW);
text->_dirty = GL_FALSE;
}
GLT_API GLboolean gltInit(void)
{
if (gltInitialized)
return GL_TRUE;
if (!_gltCreateText2DShader())
return GL_FALSE;
if (!_gltCreateText2DFontTexture())
return GL_FALSE;
gltInitialized = GL_TRUE;
return GL_TRUE;
}
GLT_API void gltTerminate(void)
{
if (_gltText2DShader != GLT_NULL_HANDLE)
{
glDeleteProgram(_gltText2DShader);
_gltText2DShader = GLT_NULL_HANDLE;
}
if (_gltText2DFontTexture != GLT_NULL_HANDLE)
{
glDeleteTextures(1, &_gltText2DFontTexture);
_gltText2DFontTexture = GLT_NULL_HANDLE;
}
gltInitialized = GL_FALSE;
}
#if USE_GLES
#define GLSL_VERSION "300 es"
#else
#define GLSL_VERSION "330"
#endif
static const GLchar* _gltText2DVertexShaderSource =
"#version "
GLSL_VERSION
"\n"
"layout(location = 0) in vec2 position;\n"
"layout(location = 1) in vec2 texCoord;\n"
"\n"
"uniform mat4 mvp;\n"
"\n"
"out vec2 fTexCoord;\n"
"\n"
"void main()\n"
"{\n"
" fTexCoord = texCoord;\n"
" \n"
" gl_Position = mvp * vec4(position, 0.0, 1.0);\n"
"}\n";
static const GLchar* _gltText2DFragmentShaderSource =
"#version "
GLSL_VERSION
"\n"
#if USE_GLES
"precision mediump float;\n"
"\n"
#endif
"out vec4 fragColor;\n"
"\n"
"in vec2 fTexCoord;\n"
"\n"
"uniform sampler2D diffuse;\n"
"\n"
"uniform vec4 color;\n"
"\n"
"void main()\n"
"{\n"
" fragColor = texture(diffuse, fTexCoord) * color;\n"
"}\n";
GLT_API GLboolean _gltCreateText2DShader(void)
{
GLuint vertexShader, fragmentShader;
GLint compileStatus, linkStatus;
#ifdef GLT_DEBUG_PRINT
GLint infoLogLength;
GLsizei infoLogSize;
GLchar *infoLog;
#endif
vertexShader = glCreateShader(GL_VERTEX_SHADER);
glShaderSource(vertexShader, 1, &_gltText2DVertexShaderSource, NULL);
glCompileShader(vertexShader);
glGetShaderiv(vertexShader, GL_COMPILE_STATUS, &compileStatus);
if (compileStatus != GL_TRUE)
{
#ifdef GLT_DEBUG_PRINT
glGetShaderiv(vertexShader, GL_INFO_LOG_LENGTH, &infoLogLength);
// If no information log exists 0 is returned or 1 for a
// string only containing the null termination char.
if (infoLogLength > 1)
{
infoLogSize = infoLogLength * sizeof(GLchar);
infoLog = (GLchar*)malloc(infoLogSize);
glGetShaderInfoLog(vertexShader, infoLogSize, NULL, infoLog);
printf("Vertex Shader #%u <Info Log>:\n%s\n", vertexShader, infoLog);
free(infoLog);
}
#endif
glDeleteShader(vertexShader);
gltTerminate();
#ifdef GLT_DEBUG
_GLT_ASSERT(compileStatus == GL_TRUE);
return GL_FALSE;
#else
return GL_FALSE;
#endif
}
fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
glShaderSource(fragmentShader, 1, &_gltText2DFragmentShaderSource, NULL);
glCompileShader(fragmentShader);
glGetShaderiv(fragmentShader, GL_COMPILE_STATUS, &compileStatus);
if (compileStatus != GL_TRUE)
{
#ifdef GLT_DEBUG_PRINT
glGetShaderiv(fragmentShader, GL_INFO_LOG_LENGTH, &infoLogLength);
// If no information log exists 0 is returned or 1 for a
// string only containing the null termination char.
if (infoLogLength > 1)
{
infoLogSize = infoLogLength * sizeof(GLchar);
infoLog = (GLchar*)malloc(infoLogSize);
glGetShaderInfoLog(fragmentShader, infoLogSize, NULL, infoLog);
printf("Fragment Shader #%u <Info Log>:\n%s\n", fragmentShader, infoLog);
free(infoLog);
}
#endif
glDeleteShader(vertexShader);
glDeleteShader(fragmentShader);
gltTerminate();
#ifdef GLT_DEBUG
_GLT_ASSERT(compileStatus == GL_TRUE);
return GL_FALSE;
#else
return GL_FALSE;
#endif
}
_gltText2DShader = glCreateProgram();
glAttachShader(_gltText2DShader, vertexShader);
glAttachShader(_gltText2DShader, fragmentShader);
glBindAttribLocation(_gltText2DShader, _GLT_TEXT2D_POSITION_LOCATION, "position");
glBindAttribLocation(_gltText2DShader, _GLT_TEXT2D_TEXCOORD_LOCATION, "texCoord");
#if !defined(USE_GLES)
glBindFragDataLocation(_gltText2DShader, 0, "fragColor");
#endif
glLinkProgram(_gltText2DShader);
glDetachShader(_gltText2DShader, vertexShader);
glDeleteShader(vertexShader);
glDetachShader(_gltText2DShader, fragmentShader);
glDeleteShader(fragmentShader);
glGetProgramiv(_gltText2DShader, GL_LINK_STATUS, &linkStatus);
if (linkStatus != GL_TRUE)
{
#ifdef GLT_DEBUG_PRINT
glGetProgramiv(_gltText2DShader, GL_INFO_LOG_LENGTH, &infoLogLength);
// If no information log exists 0 is returned or 1 for a
// string only containing the null termination char.
if (infoLogLength > 1)
{
infoLogSize = infoLogLength * sizeof(GLchar);
infoLog = (GLchar*)malloc(infoLogSize);
glGetProgramInfoLog(_gltText2DShader, infoLogSize, NULL, infoLog);