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//
// Copyright (c) 2009-2013 Mikko Mononen memon@inside.org
//
// 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.
//
#ifndef GL3COREFONTSTASH_H
#define GL3COREFONTSTASH_H
#ifdef __cplusplus
extern "C" {
#endif
FONS_DEF FONScontext* glfonsCreate(int width, int height, int flags);
FONS_DEF void glfonsDelete(FONScontext* ctx);
FONS_DEF unsigned int glfonsRGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a);
#ifdef __cplusplus
}
#endif
#endif // GL3COREFONTSTASH_H
#ifdef GLFONTSTASH_IMPLEMENTATION
#ifndef GLFONS_VERTEX_ATTRIB
# define GLFONS_VERTEX_ATTRIB 0
#endif
#ifndef GLFONS_TCOORD_ATTRIB
# define GLFONS_TCOORD_ATTRIB 1
#endif
#ifndef GLFONS_COLOR_ATTRIB
# define GLFONS_COLOR_ATTRIB 2
#endif
struct GLFONScontext {
GLuint tex;
int width, height;
GLuint vertexArray;
GLuint vertexBuffer;
GLuint tcoordBuffer;
GLuint colorBuffer;
};
typedef struct GLFONScontext GLFONScontext;
static int glfons__renderCreate(void* userPtr, int width, int height)
{
GLFONScontext* gl = (GLFONScontext*)userPtr;
// Create may be called multiple times, delete existing texture.
if (gl->tex != 0) {
glDeleteTextures(1, &gl->tex);
gl->tex = 0;
}
glGenTextures(1, &gl->tex);
if (!gl->tex) return 0;
if (!gl->vertexArray) glGenVertexArrays(1, &gl->vertexArray);
if (!gl->vertexArray) return 0;
glBindVertexArray(gl->vertexArray);
if (!gl->vertexBuffer) glGenBuffers(1, &gl->vertexBuffer);
if (!gl->vertexBuffer) return 0;
if (!gl->tcoordBuffer) glGenBuffers(1, &gl->tcoordBuffer);
if (!gl->tcoordBuffer) return 0;
if (!gl->colorBuffer) glGenBuffers(1, &gl->colorBuffer);
if (!gl->colorBuffer) return 0;
gl->width = width;
gl->height = height;
glBindTexture(GL_TEXTURE_2D, gl->tex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, gl->width, gl->height, 0, GL_RED, GL_UNSIGNED_BYTE, NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
static GLint swizzleRgbaParams[4] = {GL_ONE, GL_ONE, GL_ONE, GL_RED};
glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_SWIZZLE_RGBA, swizzleRgbaParams);
return 1;
}
static int glfons__renderResize(void* userPtr, int width, int height)
{
// Reuse create to resize too.
return glfons__renderCreate(userPtr, width, height);
}
static void glfons__renderUpdate(void* userPtr, int* rect, const unsigned char* data)
{
GLFONScontext* gl = (GLFONScontext*)userPtr;
int w = rect[2] - rect[0];
int h = rect[3] - rect[1];
if (gl->tex == 0) return;
// Push old values
GLint alignment, rowLength, skipPixels, skipRows;
glGetIntegerv(GL_UNPACK_ALIGNMENT, &alignment);
glGetIntegerv(GL_UNPACK_ROW_LENGTH, &rowLength);
glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &skipPixels);
glGetIntegerv(GL_UNPACK_SKIP_ROWS, &skipRows);
glBindTexture(GL_TEXTURE_2D, gl->tex);
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glPixelStorei(GL_UNPACK_ROW_LENGTH, gl->width);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, rect[0]);
glPixelStorei(GL_UNPACK_SKIP_ROWS, rect[1]);
glTexSubImage2D(GL_TEXTURE_2D, 0, rect[0], rect[1], w, h, GL_RED, GL_UNSIGNED_BYTE, data);
// Pop old values
glPixelStorei(GL_UNPACK_ALIGNMENT, alignment);
glPixelStorei(GL_UNPACK_ROW_LENGTH, rowLength);
glPixelStorei(GL_UNPACK_SKIP_PIXELS, skipPixels);
glPixelStorei(GL_UNPACK_SKIP_ROWS, skipRows);
}
static void glfons__renderDraw(void* userPtr, const float* verts, const float* tcoords, const unsigned int* colors, int nverts)
{
GLFONScontext* gl = (GLFONScontext*)userPtr;
if (gl->tex == 0 || gl->vertexArray == 0) return;
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, gl->tex);
glBindVertexArray(gl->vertexArray);
glEnableVertexAttribArray(GLFONS_VERTEX_ATTRIB);
glBindBuffer(GL_ARRAY_BUFFER, gl->vertexBuffer);
glBufferData(GL_ARRAY_BUFFER, nverts * 2 * sizeof(float), verts, GL_DYNAMIC_DRAW);
glVertexAttribPointer(GLFONS_VERTEX_ATTRIB, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(GLFONS_TCOORD_ATTRIB);
glBindBuffer(GL_ARRAY_BUFFER, gl->tcoordBuffer);
glBufferData(GL_ARRAY_BUFFER, nverts * 2 * sizeof(float), tcoords, GL_DYNAMIC_DRAW);
glVertexAttribPointer(GLFONS_TCOORD_ATTRIB, 2, GL_FLOAT, GL_FALSE, 0, NULL);
glEnableVertexAttribArray(GLFONS_COLOR_ATTRIB);
glBindBuffer(GL_ARRAY_BUFFER, gl->colorBuffer);
glBufferData(GL_ARRAY_BUFFER, nverts * sizeof(unsigned int), colors, GL_DYNAMIC_DRAW);
glVertexAttribPointer(GLFONS_COLOR_ATTRIB, 4, GL_UNSIGNED_BYTE, GL_FALSE, 0, NULL);
glDrawArrays(GL_TRIANGLES, 0, nverts);
glDisableVertexAttribArray(GLFONS_VERTEX_ATTRIB);
glDisableVertexAttribArray(GLFONS_TCOORD_ATTRIB);
glDisableVertexAttribArray(GLFONS_COLOR_ATTRIB);
glBindVertexArray(0);
}
static void glfons__renderDelete(void* userPtr)
{
GLFONScontext* gl = (GLFONScontext*)userPtr;
if (gl->tex != 0) {
glDeleteTextures(1, &gl->tex);
gl->tex = 0;
}
glBindVertexArray(0);
if (gl->vertexBuffer != 0) {
glDeleteBuffers(1, &gl->vertexBuffer);
gl->vertexBuffer = 0;
}
if (gl->tcoordBuffer != 0) {
glDeleteBuffers(1, &gl->tcoordBuffer);
gl->tcoordBuffer = 0;
}
if (gl->colorBuffer != 0) {
glDeleteBuffers(1, &gl->colorBuffer);
gl->colorBuffer = 0;
}
if (gl->vertexArray != 0) {
glDeleteVertexArrays(1, &gl->vertexArray);
gl->vertexArray = 0;
}
free(gl);
}
FONS_DEF FONScontext* glfonsCreate(int width, int height, int flags)
{
FONSparams params;
GLFONScontext* gl;
gl = (GLFONScontext*)malloc(sizeof(GLFONScontext));
if (gl == NULL) goto error;
memset(gl, 0, sizeof(GLFONScontext));
memset(¶ms, 0, sizeof(params));
params.width = width;
params.height = height;
params.flags = (unsigned char)flags;
params.renderCreate = glfons__renderCreate;
params.renderResize = glfons__renderResize;
params.renderUpdate = glfons__renderUpdate;
params.renderDraw = glfons__renderDraw;
params.renderDelete = glfons__renderDelete;
params.userPtr = gl;
return fonsCreateInternal(¶ms);
error:
if (gl != NULL) free(gl);
return NULL;
}
FONS_DEF void glfonsDelete(FONScontext* ctx)
{
fonsDeleteInternal(ctx);
}
FONS_DEF unsigned int glfonsRGBA(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
{
return (r) | (g << 8) | (b << 16) | (a << 24);
}
#endif // GLFONTSTASH_IMPLEMENTATION
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