libpsys

view src/psys_gl.c @ 10:0f83e882fd04

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author John Tsiombikas <nuclear@member.fsf.org>
date Wed, 29 Aug 2012 03:16:58 +0300
parents 613d2bf3ea1f
children 3871a45a4e4b
line source
1 #include <string.h>
2 #include <errno.h>
3
4 #ifndef __APPLE__
5 #ifdef WIN32
6 #include <windows.h>
7 #endif
8
9 #include <GL/gl.h>
10 #else
11 #include <OpenGL/gl.h>
12 #endif
13
14 #include <imago2.h>
15 #include "psys.h"
16 #include "psys_gl.h"
17
18 void psys_gl_draw_start(struct psys_emitter *em, void *cls)
19 {
20 float xform[16];
21
22 glMatrixMode(GL_MODELVIEW);
23 glPushMatrix();
24
25 glGetFloatv(GL_MODELVIEW_MATRIX, xform);
26 xform[0] = xform[5] = xform[10] = 1.0;
27 xform[1] = xform[2] = xform[4] = xform[6] = xform[8] = xform[9] = 0.0;
28
29 glLoadMatrixf(xform);
30
31 glPushAttrib(GL_ENABLE_BIT);
32 glDisable(GL_LIGHTING);
33
34 glEnable(GL_BLEND);
35 glBlendFunc(GL_SRC_ALPHA, GL_ONE);
36
37 if(em->attr.tex) {
38 glEnable(GL_TEXTURE_2D);
39 glBindTexture(GL_TEXTURE_2D, em->attr.tex);
40 }
41
42 glDepthMask(0);
43
44 glBegin(GL_QUADS);
45 glColor3f(1, 1, 1);
46 }
47
48 void psys_gl_draw(struct psys_emitter *em, struct psys_particle *p, void *cls)
49 {
50 float hsz = p->size / 2.0;
51
52 glColor4f(p->color.x, p->color.y, p->color.z, p->alpha);
53
54 glTexCoord2f(0, 0);
55 glVertex3f(p->pos.x - hsz, p->pos.y - hsz, p->pos.z);
56
57 glTexCoord2f(1, 0);
58 glVertex3f(p->pos.x + hsz, p->pos.y - hsz, p->pos.z);
59
60 glTexCoord2f(1, 1);
61 glVertex3f(p->pos.x + hsz, p->pos.y + hsz, p->pos.z);
62
63 glTexCoord2f(0, 1);
64 glVertex3f(p->pos.x - hsz, p->pos.y + hsz, p->pos.z);
65 }
66
67 void psys_gl_draw_end(struct psys_emitter *em, void *cls)
68 {
69 glEnd();
70
71 glDepthMask(1);
72 glPopAttrib();
73
74 glMatrixMode(GL_MODELVIEW);
75 glPopMatrix();
76 }
77
78
79 unsigned int psys_gl_load_texture(const char *fname, void *cls)
80 {
81 unsigned int tex;
82 void *pixels;
83 int xsz, ysz;
84
85 if(!(pixels = img_load_pixels(fname, &xsz, &ysz, IMG_FMT_RGBA32))) {
86 return 0;
87 }
88
89 glGenTextures(1, &tex);
90 glBindTexture(GL_TEXTURE_2D, tex);
91 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
92 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
93 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
94 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
95 glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 0, xsz, ysz, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
96
97 img_free_pixels(pixels);
98 return tex;
99 }
100
101 void psys_gl_unload_texture(unsigned int tex, void *cls)
102 {
103 glDeleteTextures(1, &tex);
104 }