Files
CGR3D-KM/OpenGL4/HeightMap.cpp
T
2016-05-23 20:50:30 +02:00

75 lines
2.0 KiB
C++

#include "HeightMap.h"
#include "stb_image.h"
#include <GL/freeglut.h>
#include <iostream>
#include <string>
GLuint imageIndex;
HeightMap::HeightMap(const std::string &file)
{
int bpp;
unsigned char* imgData = stbi_load(file.c_str(), &width, &height, &bpp, 4);
int scale = 50;
for (int h = 0; h < height; h++)
{
for (int w = 0; w < width; w++)
{
int offsets[4][2] = { { 0, 0 },{ 1, 0 },{ 1, 1 },{ 0, 1 } };
for (int i = 0; i < 4; i++)
{
float y = ((float)imgData[((h + offsets[i][0]) + (w + offsets[i][1]) * width) * 4]);
y = (y / 256.0f) * 100.0f;
vertices.push_back(Vertex{ (float)(h + offsets[i][0])*scale, y*scale, (float)(w + offsets[i][1])*scale,
0, 1, 0,
(h + offsets[i][0]) / (float)height, (w + offsets[i][1]) / (float)width } );
}
}
}
glGenTextures(1, &imageIndex);
glBindTexture(GL_TEXTURE_2D, imageIndex);
glTexImage2D(GL_TEXTURE_2D,
0, //level
GL_RGBA, //internal format
width, //width
height, //height
0, //border
GL_RGBA, //data format
GL_UNSIGNED_BYTE, //data type
imgData); //data
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
stbi_image_free(imgData);
}
HeightMap::~HeightMap()
{
}
void HeightMap::Draw()
{
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, imageIndex);
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
//glEnableClientState(GL_COLOR_ARRAY);
//glEnableClientState(GL_NORMAL_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(Vertex), ((float*)vertices.data()) + 0);
glTexCoordPointer(2, GL_FLOAT, sizeof(Vertex), ((float*)vertices.data()) + 6);
//glNormalPointer(GL_FLOAT, sizeof(Vertex), ((float*)cubeVertices.data()) + 3);
glDrawArrays(GL_QUADS, 0, vertices.size());
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
//glDisableClientState(GL_COLOR_ARRAY);
//glDisableClientState(GL_NORMAL_ARRAY);
}